1JUNIOR

2 JUNIOR

3 Science & Technology News

5 Filipino Scientists and Inventors

Medical Facts and Fallacies

9 Livelihood Technology / I�d Like to Know

10 Cyber World

14 Earth Care

16 Investigatory Projects

19 Pseudoscience

23 More Activities to Do

24 Mind Games

R E G U L A R F E AT U R E S

C O N T E N T S

BATO BALANI R O for Science and Technology is published bimonthly by Diwa Scholastic Press, Inc. Bato Balani is one of Diwa�s Scholastic Enhancement Materials (SEM

RO). The SEM RO

trademark refers to a new genre of scholastic publication, including a selection of premium-quality magazines. Copyright 2000. Articles in this publication may be reprinted provided due acknowledgmentis given. All communications should be addressed to THE EDITOR, G/F Star Centrum, Gil Puyat Ave., Makati City, Philippines, Telephone numbers: 843-4761 to 66.

S Y 2 0 0 0 - 2 0 0 1 V o l . 2 0 N o . 4

BOARD OF ADVISERS

Violeta Arciaga, Jaime F. Bucoy,

Jose C. Calderon, Victoria V. Cervantes,

Juanita M. Cruz, Belen P. Dayauon

CONSULTANT

Merle C. Tan, Ph.D.

DIWA OFFICERS

Saturnino G. Belen Jr. President

Amada J. Javellana

Executive Vice President

Enrique A. Caballero,

Reynaldo M. de la Cruz,

William S. Fernando,

Jose Maria T. Policarpio, Elma L. Ropeta,

Lourdes F. Lozano Vice Presidents

EDITORIAL BOARD

Lourdes F. Lozano Executive Editor

William S. Fernando Managing Editor

Alfie �eLf� V. Mella Magazine Editor

Virgie Naigan Art Director

Jose Valeriano P. Linay Cover Design

Jose Valeriano P. Linay Lay Out Design

Silvano C. Santiago Illustrator

PHEROMONES: CHEMICAL LANGUAGEOF THE BEASTSAnimals communicate in so many ways, one ofwhich is through the use of body scents knownas pheromones.

PERFUME: LEAVING A BIT OF YOU BEHINDDiscover the science and art of making perfumes,products that have long appealed to human�s olfactorysense.

BIOLUMINESCENCE: LUMINESCENCEIN LIVING THINGSDiscover how and why fireflies and otherorganisms produce light in their bodies.

THE BROWNIAN MOTION: MOLECULESON THE MOVEBehold the phenomenon that ended all skepticismabout the existence of atoms and molecules asactual physical entities.

Dear Bato Balani Editor:

I would like to express my

warmest greetings to the staff of Bato Balani.

I hope that you can answer my

question in any of the coming issues of your

magazine.�What is it in fireflies that ables

them to produce light?�

Thank you in advance!

Gilbert Norico

Our Lady of the Snows Institute

Dumarao, Capiz

(turn to p. 20 to know more about

bioluminescent organisms, such as the

species you�re interested in - ed)

3JUNIOR

Sodamania Outbreak

After 10 years of perfecting thepatented process, a small NewHampshire company is finallyintroducing its product to the

market—pasteurized eggs. The processinvolves passing the eggs through a seriesof warm-water baths. This kills theSalmonella, a genus of stomach-infectingbacteria that infiltrates eggs. For this reason,the eggs have a longer shelf life than theordinary ones. U.S. government has certifiedthe final product. It is expected that the

Print ads. Billboards. TV. It’s practically everywhere. Softdrinks, since its invention,

have been the toast of everyone, especially teenagers. You can have them in

bottles or in cans, or even in bottomless glasses at selected food chains. In the

U.S., the average teenage boy gulps 3 1/3 cans a day—more than 410 litres a year.

Girls aren’t much better; they sip 2 1/3 cans daily. Kids now drink twice as much softdrink as

milk; 20 years ago, it was the other way around. What most people don’t realize is the

possible end result of this sodamania: fat kids, rotten teeth and brittle bones. Okay, okay, get

real but at least moderate your soda intake. Also, remember that a glass of milk each in the

morning and in bedtime is still best even for grown-ups.

Source: Time magazine

pasteurized eggs, brandnamed Davidson’s,will be received warmly by consumers whowant safer eggs.

When will those rot-free soft-boiledsbe available in the local market? Surely itwill be a big hit in the Philippines, where anearly breakfast of tapsilog, tocilog,longsilog, and all those sort of meals coneggs are favorite choices in the menu. CallingDavidson’s! Get those eggs rolling.

Source: Time magazine

First Milk,Now Egg

4 JUNIOR

A Steaming Cup ofCoffee, Anyone?

Are you one of the millions ofpeople who can’t start the dayor spend a boring night withoutsipping a cup of coffee? After

years of conflicting research about thebenefits and harm of the most popularbeverage, most coffee drinkers couldn’t careanymore. However, you might want toconsider a study recently released in theAmerican Journal of Clinical Nutrition. Itdiscusses about the effect of unfilteredcoffee on the heart.

Researchers from the Netherlandsstudied the effects of coffee consumption

It has scared millions for years.

Researchers suspected that a craving

for a bar of Hershey’s, or any

chocolate for that matter, comes

from a desire. They alleged that certain

chemicals found in chocolates trigger the

addiction. It even said to mimic the brain

chemistry of a person in love. Ballyhoo!

claims a new study. It says that U.S. women

lust for chocolate twice as much as Spanish

women do. This recent report suggests that

craving chocolate is a learned behavior;

therefore can be unlearned.

Source: Time magazine

on homocysteine levels in the blood.Homocysteine is a naturally occurring aminoacid that forms when the body breaks downprotein. Caffeine, the main component ofcoffee, causes an elevation in thehomocysteine levels. The elevation increasesthe risk of having heart diseases. Exactlyhow the amino acid harms the heart isunclear, but researchers say that it eithermakes the blood clot or damages the liningof the blood vessels.

Good news to coffee lovers is thatincreased homocysteine levels is notpermanent. Removing the culprit—

unfiltered coffee—will help bring the levelsback to normal. Moderate coffeeconsumption is probably safer. And avoidhaving your cup too black and strong.However, for those who are at high risk ofcardiovascular diseases, why not settle for aglass of refreshing fruit juice instead?

Source: Time magazine

Chocoholics,Rejoice!

5JUNIOR

Fact: Asthma is a respiratorydisorder often of allergic origin that hasmarked symptoms such as continuouslabored breathing accompanied bywheezing, by a sense of constriction in thechest, and often by attacks of coughing orgasping. Allergens–substances that induceallergic reaction–that usually trigger it aredust, pollen, animal hairs or fur, and food towhich the person afflicted is allergic to.

Asthma is either hereditary oracquired in nature. Its symptoms arecontrollable and, though it takes quite a long

period of maintenance, asthma itself iscurable. Usually a physician will prescribeanti-asthmatic preparations, such assympathomimetic drugs (e.g. ephedrine,salbutamol, theophylline).

Ingesting lizard to cure asthma istotally absurd! Those who practice it followthese steps: 1) painstakingly catching a lizardalive; 2) roasting it or frying it without oil;3) pulverizing it using mortar and pestle;4) dissolving it in coffee, tea, or anybeverage; and 5) ingesting the concoctionas if it is a medication. In some cases, even

worse, the lizard is swallowed wholeand alive!

This practice is still prevalent in theprovinces and among the uninformed.Actually there is no scientific evidencesupporting the belief that lizard has anymedicinal value, more so is it capable ofcuring asthma.

This regimen may have just arisenfrom the lack of knowledge in science andgullibility of most of the oldfolk, who usedto associate almost anything with anythingbased on sheer coincidence.

Fallacy: Ingesting lizard cures asthma.

One of those who are deeplyinvolved with the country’s environmentalconcerns, Dr. Prescillano M. Zamoraspecializes in the study of environment,watershed management, and naturalresources policy research. His specialinterest in developmental plant anatomy andmorphology and pteridophyte biology, isthe backbone to all his significant researchactivities.

In fact, his study on Philippinemangroves published in 1981 might haveinfluenced two presidential proclamations(PP) issued in 1982. PP 2151 declaredcertain islands and parts of the country aswilderness areas while PP 2152 declaredthe province of Palawan and certain parts ofthe country as Mangrove Swamp ForestReserves.

Dr. Zamora has written and publishednear to a hundred scientific articlesconcerning the environment and haspresented his findings to scientificconferences.

He finished his degrees in Bachelorof Science in Botany at the University of thePhilippines (UP) in 1952, Master of Arts in1958, and Doctor of Philosophy in PlantAnatomy-Morphology in 1965 all at theCornell University in.

He was a recipient of two Likas-Yaman Awards in 1979 given by the thenMinistry of Natural Resources (nowDepartment of Environment and NaturalResources) for his works entitled: “ResearchStudies on Mangrove Areas in the

Philippines” and “Guide to Philippine Floraand Fauna.”

He was a member of prestigiousorganizations such as the National ResearchCouncil of the Philippines, the Society forthe Advancement of Research, the PhilippineAssociation for the Advancement of Science,the Botanical Society of America, the CropScience Society of the Philippines, the AsianEnvironmental Society, the InternationalAssociation of Plant Taxonomists, theInternational Association of Pteridologists,and the Cornell Club of the Philippines.

Presently, he is a professor at UPand Academician of the National Academyof Science and Technology.

Plant Anatomy-MorphologyPrescillano M. Zamora

6 JUNIOR

C H E M I S T R Y

e use perfume when we want ourselvesto smell fragrantly. Both men andwomen apply perfumes to their bodiesand clothing to appeal to the sense ofsmell.

Perfumes are also used insome products that normally have unpleasant odors.Industrial odorants, which are low-priced, scentedsubstances, are often added to paper, plastic, and rubberproducts to make the products attractive to buyers.

All liquids used to scent the body, like colognesand toilet waters, are sometimes considered asperfumes. But true perfumes, called extracts or essences,contain a greater amount of perfume oils.

PERFUME:

Essential Oils

Most perfumes consist of 10 to 20 percentaromatic ingredients dissolved in alcohol. Manyperfumes are blends of flower and plant oils, animalsubstances, synthetics, alcohol, and water. The exactcomposition of a perfume varies, depending on itsintended use.

The aromatic ingredients may come from plantsor animals, or they may be synthetic materials. Thedistinctive fragrances of most perfumes originate fromaromatic, highly volatile plant substances calledessential oils. These essential oils are stored in tinybaglike parts or sacs of fragrant plants.

Essential oils taken from flower petals are usedin expensive perfumes. Essential oils are also found inother parts of plants, like the bark, buds, leaves, rinds,roots, or wood. Plants whose oils are used extensivelyin perfumes include the cinnamon, citronella, geranium,jasmine, lavender, patchouli, rose, rosemary,sandalwood, and tuberose.

Methods of Extracting Essential Oils

Usually essential oil is extracted from plantsthrough steam distillation. In this process, steam ispassed through the plant material. The essential oil

turns to gas, which is then passed through tubingand cooled to make it liquid again. In another versionof this process, petals of some flowers are boiledin water, rather than by passing steam throughthem.

Another method of extracting essentialoils is solvent extraction. In this, the petals are

dissolved in a solvent. The solvent is then distilledfrom the solution to produce a waxy material that

by Ernesto Buensuceso Ferreras Jr.

Leaving a Bit of You Behind

WW

7JUNIOR

contains the oil. The waxy material is placed in ethylalcohol. The essential oil dissolves in the alcohol andrises with it to the top of the wax. Heat is applied andwhen the alcohol evaporates, it leaves a highlyconcentrated form of perfume oil.

Enfleurage is also a method of extracting floweroils. In this method, fat is spread on glass plates. Flowerpetals are then laid over the fat smear. The fat absorbsthe oil from the petals, forming a greasy pomade. Thepomade is then treated with alcohol to dissolve out theoil.

After combining all the perfume�s aromaticingredients, fixatives are added to hold the fragrancestogether. Fixatives also prevent quick evaporation or, atleast, sustain an equal evaporation rate for all thearomatic elements. Fixatives commonly come frommosses, resins, and synthetic and animal substances.Fixatives that come from animals include ambergris fromthe sperm whale, castor from the beaver, civet from thecivet cat, and musk from the musk deer.

Not only plants supply the raw ingredients forperfumes. The aromatic raw materials may also beobtained from animal products or from syntheticmaterials. For example, two flowers that do not yieldnatural oils are the lily of the valley and the gardenia. Toreproduce their distinctive fragrances, syntheticchemicals are used. In other cases, fragrances that arewholly unknown in nature are manufactured usingsynthetic materials.

Kinds of Perfumes

To dilute the ingredients, alcohol is usuallyadded to perfumes. Alcohol also carries the scents bymeans of evaporation. In fact, the ratio of scents to alcoholin a perfume solution determines the kind of the perfumeproduct.

The solutions generally known as perfumescontain between 10 and 25 percent perfume concentrate.Such products as toilet water and cologne contain about2 to 6 percent perfume concentrate. Other perfumeproducts like aftershave lotions and splash colognesusually contain only from 0.5 to 2 percent perfume oil.

Another classification of perfumes is madeaccording to one or more identifiable dominantfragrances. The most popular perfume group is the floralgroup, which blends such odors as jasmine, rose, lily of

the valley, and gardenia. The spicy group features sucharomas as carnation, clove, cinnamon, and nutmeg. Thewoody group is characterized by such odors assandalwood, cedarwood, and vetiver, a kind of aromaticgrass. An aroma of oak moss dominates the mossyfamily. Combine the woody, mossy, and spicy scentswith such sweet odors as vanilla or balsam to form theorientals group, which are usually accentuated by suchanimal odors as musk or civet. Such odors as cloverand sweet grass characterize the herbal group. Theleather-tobacco group features the aromas of leather,tobacco, and the smokiness of birch tar. The aldehydicgroup is dominated by the odors of aldehydes, whichusually have a fruity character.

The Odor You Leave Behind

The preparation of a fine perfume is a complexand exact process of blending more than 100 ingredients.After all the ingredients are combined, the perfume isoften aged like wine, sometimes for longer than a year.The slightest changes in a formula can differentiate onefirm�s products from another, and it can take years toinvent a special perfume.

Perfume preparation is an art. Perfumers mixingredients into a perfume the way musicians blendmelodies in a musical composition. And just like amusical chord, each perfume is composed of a �triad:�a top note, a middle note, and a base note. The top

8 JUNIOR

C H E M I S T R Y

1. Compton�s Interactive Encyclopedia. 1999. The LearningCompany.

2. National Geographic, September 1986.

3. Wilbraham, Antony C. et al. 1997. Chemistry, 4th Edition. California:Addison-Wesley Publishing Co.

4. World Book 2000 Millennium Encyclopedia. 1999. Chicago: WorldBook, Inc.

References:

note is the odor that you immediately perceive whenthe most volatile components of the perfume begin toevaporate. Have you smelled lemon scent upon openinga bottle of perfume? Lemon oil is a common top note.

The middle note, also called the main theme ormodifier, provides full, solid character to the fragrance.Clary, sage, and marjoram oils are often selected asmiddle notes.

The base note, also called the end note or basic,is the most persistent scent. It becomes apparent whenthe top and middle notes have faded and the least volatilecomponents of the perfume remain. Rosemary andsandalwood oils are common base notes.

When you open a perfume bottle, perfumemolecules eventually diffuse throughout the room. Thistendency of molecules to move from areas of greaterconcentration toward areas of lower concentration untilthe concentration is uniform throughout the system iscalled diffusion.

The process of gas escaping through a smallhole is effusion. This occurs as a gas escapes througha tiny hole in a container of gas, as in a perfume bottle.The rate of effusion of a gas is inversely proportional tothe square root of its molar mass. This is Graham�s lawof effusion. Subsequently, this relationship was alsoshown to be true for the diffusion of gases. The rate ofdiffusion of a gas is inversely proportional to the square

root of its molar mass. For instance, helium (with amolar mass of 4.0 g) effuses nearly three times fasterthan nitrogen (with a molar mass of 28.0 g) at the sametemperature. Applying this principle to the preparationof a perfume, it is obvious that to diffuse faster the topnote must consist of a blend of ingredients that has alower molar mass than the main theme or the base.

What you perceive as you open the bottle andapply perfume on your skin is the top note. The top noteusually has a sharp and intoxicating smell. It is fleetingand gives way to the main theme of the fragrance.Perfumer makers say that a good fragrance is one thatdiffuses and lasts. In this way, a perfume appeals bestto the sense of smell.

1. How do perfumer makers blend numerous ingredients into a perfume product that diffuse well.

2. Give one method of extracting essential oils from plants. Briefly describe the process.

3. Among the perfumes that you have used or smelled, which appealed to you most? Classify it according to fragrance.

distillation � the vaporization and subsequent condensationof a liquid

extract � a substance or preparation obtained by distillation orother chemical means

molar mass � refers to the mass of a mole of any element orcompound; also called gram formula mass

solvent � a fluid that dissolves a specified substance

9JUNIOR

Until 1890, yellow was not the predominant color ofpencils. L&C Hardmuth Co. of Austria introduced its brandof pencil with such quality that it became the standard forothers to follow. Brandnamed Koh-i-noor, derived fromthe fabulous Indian diamond, this pencil was painted goldenyellow. It was patterned after the erstwhile Austro-Hungarianflag bearing the same color of the pencil and its lead. Itscommercial success established yellow the symbol of qualityin pencil. By the way, pencil contains no lead, or plumbum,at all. The writing tip of the pencil is made of graphite, a softcrystallized carbon mixed with clay as hardener.

INGREDIENTS4 medium-sized bangus (milkfish)saltatswete for coloring

PROCEDURE

1. Remove scales and wash the fish.

2. Eviscerate the fish by insertingforefinger or a curved knife about ½ inchwide through the gill flap of each fish.

Homemade Tinapang Bangus

3. Make a small slit below and betweenthe gill flaps through which the rest of theinternal organs can be hooked out.

4. Wash the fish again and immerse in10-percent brine (1/3-cup salt to 3 cupswater) for about an hour. This is to leachout as much blood and slime as possible.

5. Put the fish into 60-percent brine(½-cup salt to two cups water) for aboutthree hours.

6. Remove the fish from the brine andrinse with water. Do not soak.

7. Lay the fish on a grill or bamboo rack.8. Let the fish dry out in the sun with a

good breeze blowing on it. Turn the fishregularly.

9. Dry the fish for about four hours oruntil the surface moisture is gone. Wait tillskin glosses or pellicle (thin film) forms overthe skin.

10. Brush the fish with atswete.

11. Smoke the fish for six to eight hoursat a temperature of between 32° and 38° C.

Be it in the form of relyeno, daing, or tinapa, bangus (or milkfish) is a common viand present in a typical Filipino family platter. Youcan buy the fish already in the form of daing or tinapa from either the market or a street vendor. However, for a change, why not try makingit yourself. With just a few ingredients, you can make your own homemade tinapang bangus right there in your own backyard!

Q: Why are most pencils colored yellow?

A:

Katrina Bianca T. AranzamendezAteneo de Davao University

10 JUNIOR

Often in programming there are things we wantthe computer to do over and over again until we saystop. Now we could do this using an IF-THEN statement.But then can you imagine using an IF-THEN over ahundred times? Luckily there is a simpler way calledlooping. A loop is a programming technique that allowsyou to do the same thing a given number of times.

Okay, the best way to illustrate this is to usean example. Let�s say you want to display your name5 times on screen. You can write a program that lookslike this:

CLS INPUT �What is your name�, name$PRINT name$PRINT name$PRINT name$PRINT name$PRINT name$END

Or you can write one that looks like this:

CLSINPUT �What is your name�, name$FOR A = 1 to 5PRINT name$NEXTEND

The second code is definitely shorter andactually much simpler. Now let�s try to analyze whatthe second program does.

The command is FOR-NEXT and it allows seriesof command lines to be repeated. The syntax andsample are as folllows:

Loops!!!by Wacky Salazar

11JUNIOR

SYNTAX: FOR <variable> = <startvalue> TO <end value><�commands�>NEXTSAMPLE: FOR A = 1 to 20PRINT ANEXT

The command should be easy enough and witha little practice you should get the hang of it. The variableshould be a numeric variable because the valuesassigned to it are numbers. Then the starting value isthe first value assigned to the variable. Examine theFOR-NEXT statement and look at the table.

FOR I = 5 to 10PRINT �VISIT WWW.BATO-BALANI.COM onthe Internet�NEXT

TABLE:LOOP NUMBER VALUE OF IDISPLAY1 5 VISIT WWW.BATO-BALANI.COM on the Internet2 6 VISIT WWW.BATO-BALANI.COM on the Internet3 7 VISIT WWW.BATO-BALANI.COM on the Internet4 8 VISIT WWW.BATO-BALANI.COM on the Internet5 9 VISIT WWW.BATO-BALANI.COM on the Internet6 10 VISIT WWW.BATO-BALANI.COM on the Internet

Note that I will hold the values of 5,6,7,8,9,10.A total of 6 numbers, so the code executes 6 loops.But if we look at the output it displays the phrase �VISITWWW.BATO-BALANI.COM on the Internet� six timeson screen.

There is more!!! It is also possible to �skip�values. This is done by adding the STEP command:

SAMPLE: FOR A = 2 to 20 STEP 2PRINT ANEXT

This program displays all even numbers from1 to 20. Actually the STEP value is always there, if youdo not specify a STEP value by default it is set to one.What happens here is that when the loop reaches theNEXT statement, it will add the step value to the currentvariable. So if A is 2 and the step value is 2 then thenext value for A will be 4 and so on.

LOOP NUMBER VALUE FOR A STEP VALUE1 2 22 4 23 6 24 8 25 10 26 12 27 14 28 16 29 18 210 20 2

As you can see there are only 10 loops in thissequence.

� Want a little more magic? But before you readon, try this exercise first: Write a program that will countfrom 1 to 20. That should be easy enough.

Okay, the next exercise should challenge youa bit more. Write a program that will count backwardsfrom 20 to 1.

Well, the answer to the first exercise is here:CLS FOR X = 1 to 20PRINT XNEXTEND

Now the answer to the second exercise is a bittricky. The code should look the same as the one abovewith these modifications. Change your start value to 20and your ending value to 1 and then set your STEPvalue to negative one. By using a negative number youare subtracting from the current value of your variablerather than adding.

Try creating otherprograms and practice usingthe FOR-NEXT loop.

12 JUNIOR

uring its mating ritual, a queenhoneybee flies away from its nest, givingoff an odor that male bees, or drones,find irresistible. The drones follow thequeen on its rising, whirling flight. Being

streamlined the queen flies faster than the drones. Manyof the drones give up the pursuit. The queen choosesone to mate from those who are able to follow her. Aftera few seconds her mate falls dying to the ground, andshe chooses another.

Odors produced by an animal and which inducepsychological or behavioral changes in the samespecies, in this case, mating in honeybees, are calledpheromones. Pheromones are the chemical languagethat animals, especially insects, use to organize theircomplex societies.

Animals Communicate

One of the many ways animals communicateis through chemical means, that is, producing odorsfrom skin and body glands, feces, and urine. Manymammals, fishes, and insects secrete pheromones tocommunicate with others of their species. Many animals,for example bees and moths, release pheromones intothe air as sexual attractants.

Most mammals are able to maintain theirterritories and identify one another by marking with scentglands, defecating, or urinating. The odors they secreteare used to give alarm, to select food, and to mate.Have you seen dogs urinating in particular spots, likerocks and posts? Dogs mark territories by urinating. Acat marks its owner with facial and rump glands as itrubs its owner�s leg.

By secreting pheromones, animals mark theirterritories, assert their dominance, and communicatetheir sexual status. Humans, too, produce pheromonesfrom glands located in the armpits and around the faceand genitals.

Animals also mark by pheromones to createscent trails, to identify members, and to warn strangersto go away. The messages are imperceptible to ushumans, yet in the wild it�s a matter of life and death formost animals. For instance, the reindeer�s scent glandsbetween their hind toes help them leave scent trails forthe herd. Rabbits mark with their chin glands. A guineapig could be able to tell whether a drop of urine camefrom another male or female guinea pig, as well aswhether the other one is a friend or foe. A wildebeestsniffing her newborn calf is forming a permanent olfactorybond with her offspring, which is also smelling her odor.Bonding is necessary. Any calf that has becomeseparated from its mother during an annual migrationfalls easy prey to lions and other predators.

The queen honeybee preserves her colony byexuding an odor that inhibits worker bees from layingeggs and constructing queen cells. Should you be stungby a honeybee, run for cover; the odor of the stinger isan alarm pheromone that can trigger a mass attackfrom the hive. Fire ants prepare paths to food by draggingtheir stingers across the ground to lay down a scent

PHEROMONES:

DDby Ernesto Buensuceso Ferreras Jr.

Chemical Language of the Beasts

13JUNIOR

trail for the colony to follow. Termites would emit an alarmpheromone that calls repair termites to a hole in theirmound.

At first it was believed that insects respond toa single chemical stimulus, but pheromones oftenconsist of complex blends of compounds. For instance,the female oriental fruit moth combines a chemicalinhibitor with her sexual pheromone to attract males ofonly her own species. The chemical combination servesto discourage males of closely related species.

However, given the usefulness of pheromones,it has its own disadvantages. The odor fades rapidly,making it an inadequate means of communication insituations that may change rapidly. In wind and rainconditions, pheromone effectiveness is also considerablydecreased.

The molecules of some odors are too heavy tobe sniffed. They must be licked and pump into anolfactory apparatus called vomeronasal organ; in mostanimals it lies above the hard palate of the mouth. Aviper will pursue a vole by flicking its tongue along thescent trail and then into its vomeronasal organ throughtwo slits in the roof of its mouth. Have you seen a bullsniff the air and come trotting across the meadow to acow in heat? Once beside her, he licks her genital area,and his vomeronasal organ probably prompts the finalact. His hypothalamus triggers his pituitary, and thepituitary instructs his gonads to produce the hormonetestosterone.

Synthetic Pheromones

By studying the role of pheromones in animalbehavior, scientists are able to apply pheromones togood uses. For instance, chemists have developedsynthetic pheromones that are used to control insectpests. Unlike many pesticides, pheromones do not harmthe environment. Artificial female pheromones of suchinsects as moths and beetles are used to bait trapsthat capture males of the same species. In anothermethod of pest control, called communication disruption,farmers spread their crops with fibers soaked in an insectpheromone. The odor of the pheromone prevents themale insects from finding the females for mating.

An area of pest-control research that hasreceived much attention in recent years involves baitingtraps with the pest�s own sex attractants. Pheromone

References:

1. Gibbons, Boyd. �The Intimate Sense of Smell.� NationalGeographic, September 1986.

2. Campbell, Neil et al. Biology: Concepts and Connections, 2nd

Edition. 1997 California: Addison Wesley Longman, Inc.3. Compton�s Interactive Encyclopedia. 1999 The Learning

Company.4. World Book Millennium 2000 Encyclopedia. 1999 Chicago:

World Book, Inc.

gonad � a reproductive gland (as an ovary or testis) that producesgametes

olfactory � relating to the sense of smellstinger � a sharp organ (as of a bee) that is usually connected

with a poison gland or otherwise adapted to wound by piercingand injecting a poison

testosterone � a hormone produced especially by the testes ormade synthetically and that is responsible for inducing andmaintaining male secondary sex characters

1. Cite other areas where pheromones are artificiallyapplied to attract animals.

2. Name animals that secrete pheromones as a meansto communicate.

3. Observe your pet dog and cats, if you have any. Namespecific behavior or act that they do in connection withpheromones.

4. In what areas of the human body are pheromonesproduced?

traps have been used extensively against the fruit flyand gypsy moth. Pheromones are also being used toattract and trap pests that infest stored foods and grains.Pheromone traps act as a mating call. Once inside, theinsect is trapped and cannot escape.

In the field of artificial breeding, farmers spraysynthesized boar saliva at a sow. A sow in heat willstand to be bred if she smells the boar�s saliva andbody odor and feels her mate�s pressure on her back.Farmers apply back pressure and artificially inseminatethe sow.

14 JUNIOR

he use of the chemical cyanide infishing is probably the easiest wayto have a good catch. Tablets ofcyanide are dissolved in sea waterin plastic squirt bottles and thesolution is puffed into the coral reefs.

The fish will be disturbed and made to come out of thecoral reefs, their hiding place. The cyanide will stun themand they can be captured alive.

Cyanide is a highly poisonous chemical. Its usein fishing started in the Philippines during the 1960�s tomeet the growing demand for aquarium fish in Europeand North America. Later on, cyanide was also used tocapture live larger fish such as grouper, wrasses, rockcod and snapper that were worth higher than dead fish.

Cyanide fishing is considered illegal in all Indo-Pacific countries but the high premium paid for live reeffish, weak enforcement capacities, and seeminglyinevitable corruption have spread the use of the poisonacross the entire region where the vast majority of coralreefs lie.

Approximately more than one million kilogramsof cyanide has been squirted onto Philippine reefs sincethe 1960�s. Cyanide fishing is now confirmed to be inpractice, or suspected in countries stretching from thecentral Pacific to the shores of East Africa.

Also known as hydrocyanic acid and prussicacid, cyanide is actually hydrogen cyanide. It is acolorless liquid with a bitter-almond odor and extremelypoisonous. The chemical formula of hydrogen cyanideis HCN and the term �cyanide� applies to the�CN structure.

It melts at -14° C (6.8° F) and boils at 25.7° C(78.2° F). The compound mixes with water, alcohol, and

ether in all proportions. HCN molecules can combine toform a black solid when impurities are present. Thereaction may be explosive unless inhibited. Hydrogencyanide is also flammable and can form explosivemixtures with air. It was once produced from the pigmentPrussian blue where it got its secondary name. Now itis prepared commercially by the reaction of methanewith ammonia in the presence of a platinum catalyst.

Hydrogen cyanide is commonly used in theproduction of acrylonitrite - a starting compound forvarious products - but the process was replaced byanother using propylene. It is also used in the makingof plastics and several important cyanide compounds.The latter include sodium cyanide (NaCN) and potassiumcyanide (KCN), which are essential in metallurgy. Theyare used in recovering gold and silver from ores, andNaCN is used in the hardening of steel. Several cyanide

An Ecological CatastropheCYANIDE FISHING:An Ecological CatastropheCYANIDE FISHING:

TTby Raymond A. Oliveros

15JUNIOR

compounds are employed in the electroplating of metalssuch as silver, gold, copper, and platinum.

According to systematic scientific tests, theimpact of cyanide on reefs is little but the tests alsoshow that cyanide kills corals, and it has toxic effectson fish as well. Usually, the lethal effect of cyanide onthe reef comes from countless scuba-diving operators,field researchers, and cyanide fishcatchers themselves.

The process of cyanide fishing itself indisputablywreaks havoc on coral reefs. After divers puff the solution,the fish often flee into crevices, obliging the divers tohammer the reefs apart to collect their stunned preys.

Cyanide also kills coral and reef invertebratesalong with many nontarget fish. Large percentages ofthe fish caught alive die while being transported becauseof their weak state as a result of cyanide poisoning.

Deadly in any marine environment, the spreadof cyanide fishing is particularly tragic in the countriesof the Indo-Pacific. The region is considered as the globalcenter of marine biodiversity for corals, fish, mollusks,and reef invertebrates. A considerable squirt of cyanidesolution in this area would have a catastrophic effect onour ecology.

Moreover, exposure to cyanide poses risks onhumans. Its careless use often shoddy compressed-airdiving gear by untrained divers. A few milligrams of thesubstance can be rapidly fatal to humans because itblocks the ability of cells to use oxygen.

Cyanide fishing also threatens the livelihood ofpoor coastal people in the region, where dependenceon fish is very high and fisheries provide millions withincome.

Based on the experience of the Philippines, theonly country so far to take concrete action againstcyanide fishing, the probem can be remedied. A uniquepartnership between the government and the InternationalMarinelife Alliance (IMA), a local non-governmentalorganization was created under the country�s CyanideFishing Reform Program (CFRP).

The program has trained thousands offishcatchers to use alternative methods of fishing suchas fine-mesh barrier nets draped over a reef section to

1. Microsoft Encarta Encyclopedia2. International Marinelife Alliance3. World Resources Institute

References:

catch aquarium-sized fish and hook-and-line techniquesto catch larger fish for the restaurant trade.

The government has intensified enforcement ofanti-cyanide fishing laws by establishing a network ofcyanide detection laboratories operated by IMA. Thelaboratories randomly sample fish exports at shipmentpoints throughout the country and monitor all aspectsof the trade.

New regulations are being created to maketesting a requirement for all live fish exports and totighten controls on import and distribution of cyanide.A public awareness campaign in the media and publicschools is helping to educate Filipinos about the valueof coral reefs and the threats posed by cyanide andother destructive fishing practices. Although cyanidefishing has not ceased in the Philippines, it has certainlybeen reduced as a result of these efforts.

According to IMA the difficulties in stoppingcyanide fishing should not be underestimated. �It isimportant to note, though, that people have long capturedand sold live fish without using cyanide, and they stilldo in many places such as the Caribbean and Hawaii,where live aquarium fish have been collected with fine-mesh nets for decades,� the alliance said.

The group added, �Nothing is intrinsically wrongwith a cyanide-free live-fish trade as long as it is practisedat sustainable levels, and protects the coral reefecosystem that provides fish habitat.�

But cyanide fishing is fast becoming a deeply-rooted tradition in the Philippines, handed down fromoldfolk to new generation. The challenge is mainly onthe shoulders of the new and younger generation offishcatchers. It is about time to eradicate cyanide fishing,along with other counterproductive traditions, and replaceit with new methods feasible in maintaining balance innature. Unless humans cease on their environment-unfriendly ways of dealing with their lives, an ecologicalcatastrophe is not far from being overblown into a globaltragedy.

16 JUNIOR

I N C O O P E R A T I O N W I T H T H E

DEPARTMENT OF SCIENCE AND TECHNOLOGY

The Feasibility of UsingIndigenous Dyestuffin the Production ofHighlighter Inks

ABSTRACT

This study was conducted in order to

determine the feasibility of using indigenous

dyestuff in producing quality highlighter

inks. Three plants were chosen as sources

of dyes - the San Francisco leaf, flower of

the gumamela, or shoeflower (Hibiscus

rosa-sinensis), and the luyang dilaw, or

yellow ginger, or turmeric (Curcuma longa).

In order to extract the dyes, the plants were

boiled. Ink production using the San

Francisco dye was continued since it was

observed to be the most stable among the

samples.

17JUNIOR

Inks with different ratios of dye

(solute) to water (solvent) were produced.

The solutions were tested on paper. A survey

was done on which treatment students

preferred. The samples were judged based

on a set of criteria which included evenness

of color, drying time, smearing, odor, and

texture of paper after marking.

It was also observed that in some

criteria, such as odor and smearing, the ink

that was produced using indigenous

dyestuffs was considered acceptable. It was

then concluded that indigenous dyestuff

could be used to produce highlighter inks,

though some improvements could still be

made in the production of the ink.

INTRODUCTION

Branded highlighters are

relatively expensive because the materials

used in manufacturing them are imported

from other countries. Also, the synthetic

chemical components present in the ink may

be harmful to humans and the environment.

These are the primary reasons why there is

a need to look for alternative sources of

substances used to make inks.

This experiment aims to develop a

product that would serve as an alternative

for expensive and environmentally-

hazardous commercial markers. The study

deals only with high lighter ink using plant

components. Not all of the experimental inks

may be made purely of plant materials. A

mixture of existing synthetic materials and

experimental plant materials may be used

depending on the clarity desired. Feasibility

tests done were semi-quantitatively due to

unavailability and inaccessibility of testing

equipment.

REVIEW OF RELATED LITERATURE

Ink is a pigmented substance of

viscous consistency and liquid state used

for writing, printing, or drawing. All inks

contain four basic components: the colorant,

which contains the pigment; the vehicle,

wherein the color is dispersed; the additives

for binding the ink to the surface and

preserving its color; and the solvent.

The initial steps in creating ink are

boiling (70° to 80° C) of water and addition

of glycol, dye, wetting agent and phenol.

After pouring the ingredients, the ink is then

cooled to ambient temperature then filtered

under vacuum or through filter press. This

process shall be the basis of the experiments.

A dye is a natural or synthetic

substance used to color various materials,

especially textiles, leather, and food. Natural

dyes are obtained from plants, animals, and

some minerals that occur naturally. These

have been almost entirely replaced in modern

dying by synthetic dyes. Most of these are

prepared from coal tar, being formed from

aromatic hydrocarbon such as benzene, from

which indigo is derived, or anthracene, which

yields alizarin. Alizarin is a mordant dye

and the color it yields depends upon the

mordant used. Some materials like silk or

wool can be colored simply by being dipped

in dye, which is a kind of direct dye, while

others, including cotton, commonly require

the use of mordant.

The San Francisco leaves, the

gumamela, and the luyang dilaw contain

green, red, and yellow pigments respectively.

These dyes are used for coloring paper and

textile since they are thin and transparent.

A mordant is a chemical substance

which, when added to plant dyes, modifies

or completely transforms its color. Those

mordants which may be safely used in

testing for colors are: citric acid (lemon

juice), acetic acid (vinegar), and bicarbonate

of soda or sodium bicarbonate (washing

soda). The amount of mordant to be used

depends upon the specific hue desired.

There is no need to use a mordant if

modification of color is not required,

although the addition of mordant

significantly increases the plant’s color

potential.

Extracting color or dye may be done

by soaking and boiling the plant material

for about 20 minutes in order to release its

color. But some plant materials, specially

the reds, may yield a brown color when

exposed to a temperature of more than

80° C, so boiling is not advisable.

Soft or artificially softened water

(obtained by adding washing soda) allows

plants to produce more color. Many plants,

however, produce dyes that are simply too

dull, weak, or impractical to use.

Although most dyes used today are

nontoxic, the effluent from dyeing processes

can be harmful to the environment.

Wastewater from dyeing processes contains

unused dye and other chemicals. Our laws

require textile plants to treat wastewater

before discharging them.

METHODOLOGY

The San Francisco leaves, luyang

dilaw, and gumamela were washed,

chopped, and then weighed (all done

separately for each sample). The equipment

for dye extraction, such as blender, hot plate,

18 JUNIOR

steam bath, triple beam balance, and beakers,

were also prepared. At the same time,. used

pen casings were collected and drained of

their ink. The samples were then dried in the

oven in preparation for the preliminary

testing.

The samples were dissolved in water

and observed for color solubility and

stability. The resulting colors of the samples

were also noted. It was observed that the

extract from the San Francisco leaves is the

most stable among the three sources.

The San Francisco extract was diluted

with water in the ratio of 1 ml (water) : 4

grams (extract) and 1 ml (water : 2 grams

(extract). The solution was ground using

mortar and pestle to obtain the desired

texture. At the same time, water was heated

at about 70° to 80° C. The ethylene glycol,

dye, wetting agent, and phenol were then

gradually added to the mixture. The ink was

allowed to cool.

Before placing the ink in marker

casings, the mixture was tested on paper.

The ink was observed for (1) texture of the

paper after marking, (2) evenness of color,

(3) smearing, and (4) odor.

The inks were put into felt-tipped

casings of various sizes. The pens were

applied on different textures of paper in order

to test their efficacy. Five rankings were

made for four different characteristics: color

quality, texture of paper after marking, odor,

and ink consistency on paper.

The Friedmann’s Test was used to

test the significance of the null hypothesis.

The null hypothesis states that there is no

significant difference between commercial

marker inks and the experimental marker

ink.

RESULTS AND DISCUSSIONS

During the preliminary testing of the

samples for solubility and stability of color,

it was discovered that the gumamela extract

is insoluble with water. The use of this dye

was thus discontinued. The luyang dilaw,

on the other hand, was dry enough and its

percentage yield was evidently very small.

Moreover, the luyang dilaw sample

appeared somewhat toasted, destroying its

original bright yellow color. Only the San

Francisco leaves showed the desired

characteristics of an ideal ink. Although it

had a relatively small percentage yield, the

San Francisco leaves had the most stable

color among the samples. The green pigment

in the dye remained after drying in the oven.

Consequently, the ink mixture only

contained the San Francisco dye.

The ink mixture, which consisted of

ethylene glycol (5 mL), water (20 mL), NIS

(0.25 mL), and the San Francisco dye

(3 mL) needs further straining because of

the presence of fibrous filaments.

The 20 panelists, chosen randomly

for testing, ranked each solution within the

range of 1 to 5, with 5 being the least

favorable in terms of quality. The results

indicated that commercial ink is still the most

preferred among the ink samples because

of its fluorescent properties. But it can be

concluded that the experimental ink was able

to achieve the other characteristics of

highlighter inks, such as clarity, minimal

smearing, and transparency. The odor and

color intensity may still be improved.

SUMMARY AND CONCLUSION

The most efficient process of

extracting dye from plants is through boiling,

steam bathing, and oven drying. Water is

the most suitable solvent since this does not

have any effect on the smearing property of

highlighter ink.

The San Francisco dye did not have

enough color to intensify its effect on paper.

This, together with other factors such as

odor, texture of paper after marking, and

smearing, was one of the primary reasons

why the commercial brand was favored

more. However, the experimental ink was

able to meet the basic standards of

transparency and minimal smearing. It can

also be concluded that the use of indigenous

dye as a substitute for commercial ink is

feasible.

RECOMMENDATIONS

Other indigenous dye-yielding plants

may also be tested. Other pigments with

stronger color may be found in other plant

sources.

Researchers:John Paul Emmanuel F. BayhonFaith Anne V. BuenaventuraRafael L. JoverAnna Marseille D. GabuteroKathryn Mae Ogali Pujanes

Ms Juanita CruzResearch Adviser

Note:No part of this article may be used orreproduced in any form whatsoever withoutwritten permission from the PhilippineScience High School, Diliman, Quezon City,except in the case of brief citation asembodied in the laws of scientific articlesand reviews.

19JUNIOR

growing fad in the herbal ortraditional medicine industryis aromatherapy. This practiceis based on the belief thatfragrances, particularly thosefrom oily plant extracts, can

alter the mood or improve the individual’shealth or appearance. Aromatherapy claimsto provide relief from stress, increase thebody’s immune system, and relieve or curebodily ailments.

Strictly speaking, aromatherapyincludes the inhalation of Vicks VaporubTM,a topical mentholated balm, for instance, thatcan help relieve the symptoms of a cold orcough. But aromatherapists claim to not onlyrelieve symptoms but cure the illness itself.A lot of pseudoscientific explanation triesto explain the rationale for the practice, andesoteric claims of “restoring balance andharmony to one’s body and to one’s life”fails to come up with scientifically acceptabletesting procedures.

Aromatherapy is usually practicedalongside massage therapy, where oilessences are rubbed on a person’s body.By extension, fragrant oils, incenses and

aromatic candles are often prescribed byaromatherapists to be used for dailytherapies, purportedly to “foster a spiritualenvironment and restore harmony to theirenergy flow.”

But such claims are unverifiable. Andwhile scents or aromas can influence aperson’s moods at certain times (notice howyou perk up when you smell the scent oforange or lemon in a room, or how yourstomach juices begin to churn when yousmell odors from the dinner table, forinstance), these claims of aromatherapy’shealing power are non-testable new agemythology.

Even granted that some of thesefragrant oils have antiseptic and antibioticproperties, yet aromatherapists can onlyprovide anecdotal evidence of their supposed“cures.” For instance, they claim thatchamomile, a common fragrant herb usedby aromatherapists, is good for insomnia iftaken in a late bath. But no testing has beenmade to identify whether it was thechamomile or the bath or the lateness of thehour that caused sleepiness. Or to purifydirty water, they recommend boiling the

water and adding rosemary, sage or thymebefore drinking. The question is, which partof the process really did the purifying, theboiling or the adding of these fragrances?

A number of medical and scientificinstitutions are currently looking into thephysiological effects of smell. The sense ofsmell, together with the rest of the 5 senses,do, indeed, influence the mood and behaviorof humans. But the issue againstaromatherapy is that of promising too muchto those who may be in need of legitimatemedical treatment. As an aid to relaxationand as a trigger to novel physical sensations,aromatherapy can, indeed, be a boon. Butas a significant source for healing illnesses,— that is best left to scientifically trainedmedical practitioners.

References:1. Aromatherapy: Making Dollars out of

Scents, Stephen Barrett, M.D.2. www.quackwatch.com3. Alternative Healthcare: A Comprehensive Guide Amherst, NY: Prometheus Books 1994

AAAromatherapyAromatherapy

“Pseudoscience” literally means “false science.” Therefore, it is best for the public to be made aware of the facts behind

pseudosciences – practices and beliefs that have no reliable scientific bases. These include false beliefs that are, almost always, resultsof the ignorance and gullibility of the oldfolk, who tend to rely strongly on “coincidence mentality.” However, baffling it is to know thatdespite the innovations and developments in science – the foundation of human knowledge – many continue to patronize pseudosciences.

This section aims to expose these pseudosciences, which do not only hamper progress, but may also pose harm to the healthand sound judgment of those who get victimized by it. But don’t worry, just a dose of real science cures the most ignorant of minds.

20 JUNIOR

C H E M I S T R Y

LUMINESCENCE IN LIVING THINGS

ave you already seen fireflies atnight? Aren�t they adorable with theirtiny specks of light in the dark? Ithas something to do with their specialability to emit light. But have you ever

wondered how a fireflyproduces the light from the

lower part of itsabdomen? And why?

Also did you knowthat there are otherorganisms asidefrom the firefly that

exhibit this kind ofphenomenon?

This ability offireflies, as well as some other living

things, is a phenomenon known asbioluminescence. Yes, there existother living things aside from thefirefly that have this ability to glow inthe dark. It�s just that the firefly is themost commonly seen among these�bioluminescent� organisms.

The term �bioluminescence�is derived from a broader conceptknown as chemiluminescence.

Chemiluminescence, from theword chemi, which means

�chemical;� andl u m i n e s c e n c e ,which means �givingoff light,� is the ability

of certain objects to emit light throughthe means of chemical reaction. Theseobjects include the luminous glowsticksused by mountain hikers and seen inconcerts, as well as certain organismsthat are known to produce light in theirbodies. The phenomenon can besomehow likened to the process ofincandescence, in which an electriccurrent passes through the filament of theincandescent bulb, causing the thin metalwire to get extremely hot. During thisinstance that the filament is in a highenergy state, its electrons become excited.After a while, as the electrons reach a stableand relaxed energy state, the filament then gives offexcess energy in the form of light. But in incandesence,no chemical change is taking place. Inchemiluminescence, on the other hand, chemicalreaction is the main factor. For example, in the case ofthe firefly, it is remarkable to know that the energyreleased from its process of chemiluminescence is inthe form of light with very little or no heat at all. That iswhy the glow it produces is often termed as �cold light.�In most chemiluminescent organisms, this cold light issaid to be produced through the action of an enzyme,known as luciferase, on its substrate called luciferin(In Latin, lucifer means �light-bearer.�). The chemicalreaction involves the oxidation of luciferin, a processwhich results in the emission of photons, producing thelight observed in the organisms. The whole process isbasically the same in all bioluminescent organisms.However, some make use of calcium- activatedphotoproteins instead of luciferases.

by Alfie Vera Mella

HH

21JUNIOR

Not a rare phenomenon, the chemiluminescencein living things, or bioluminescence, is well observed ininsects, particularly among members of Lampyridae, afamily of beetles that includes the lightning bug and thefirefly; and in some species of bacteria, fungi, sponges,coelenterates, crustaceans, fish, and lower plants. Asa matter of fact, about two-thirds of the entire deep-seafishes exhibit bioluminescence. However, thephenomenon is yet to be seen in mammals, birds, andother higher forms of animals.

But why? What do these organisms exhibitbioluminescence for?

The use of bioluminescence varies fromorganism to organism. In the case of the firefly, scientistsbelieve that the luminous light in the lower part of itsabdomen is a mating call to other fireflies, very importantin their courtship. Actually the firefly has about130 distinct codes of flashes used in communicatingwith its fellow fireflies. Some bioluminescent mushroomsregard their light important in the propagation of theirspecies. The luminous light attracts insects that canspread the fungi�s spores. The Photoblepharonpalebratus and the angler fish, both deep-seabioluminescent fish species, do not produce their ownlight but instead the bioluminescent bacteria that live inspecial pockets on their bodies are the ones providingthem luminosity. The palebratus uses this symbioticrelationship to see through the dark, in the deepestportions of the sea. The light also keeps a school ofpalebratus together by making each individual fish easierto see. The angler fish, on the other hand, uses thelighted spot on the end of its antenna to lure smallerfish. When another fish comes close to investigate the

1. http://www.biology.lsa.umich.edu/~www/bio311/projects

2. http://www.sciam.com/askexpert/chemistry/chemistry17

incandescence - a process that involves excitement of theelectrons of an object by an electric current resulting toradiation of heat and light

filament - a thin conducting wire with a high melting point in anelectric bulb

enzyme - a protein acting as a catalyst in a specific biochemicalreaction

catalyst - a substance that increases the rate of a reaction withoutitself undergoing any permanent chemical change

substrate - the substance upon which an enzyme acts

1. Differentiate luminescence from incandescence.

2. Describe how chemiluminescence occurs.

3. Give some uses of bioluminescence.

References:

source of the light, the angler fish easily snaps its preywith its jaws. Bioluminescence also helps other animalsin their reproduction. Being luminous, the unfertilizedeggs laid by the female can be easily seen by the maleto fertilize them. These are just some of the animalsthat exhibit bioluminescence, a phenomenon thatseems only for the fascination of the curious ones.However, as greatly evidensed by the diversity of itsuses, bioluminescence is, indeed, of great value to thelife cycle of those living things that exhibit it. So thenext time you see fireflies glowing brilliantly in the dark,you now know where their light is coming from.

22 JUNIOR

C H E M I S T R Y

he irregular motion of small suspendedparticles visible in a microscope, theBrownian motion, or Brownianmovement, is a molecularphenomenon named after the Scottishbotanist Robert Brown. Earlier, other

scientists had already observed the phenomenon but itwas Brown1 who in 1827 made a thorough study andunderstood the molecular motion.

Brownian motion is a macroscopicmanifestation of diffusion, the physical process in whicha substance tends to spread steadily from regions ofhigh concentration to regions of lower concentration.So it is possible to study diffusion by simulating themotion of a Brownian particle and computing its averagebehavior. A few examples of diffusions studied in termsof Brownian motion include the diffusion of pollutantsthrough the atmosphere, the diffusion of �holes� (minuteregions in which the electrical charge potential is positive)through a semiconductor, and the diffusion of calciumthrough bone tissue in living organisms.

�Classical Brownian motion� is the randommovement of microscopic particles suspended in a liquidor gas. Brown was investigating the fertilization processin Clarkia pulchella, a newly discovered species of flower,when he noticed a �rapid oscillatory motion� of the pollengrains suspended in water under the microscope.

Brown was also startled to observe that pollenof plants dead for over a century showed the samemovement. Further study revealed that the same motioncould be observed not only with particles of other organicsubstances but even with chips of glass or granite orparticles of smoke.

The significance of Brownian motion becameapparent in the beginning of the 20th century, upon theinvention of the ultramicroscope. The instrument enabledscientists to further observe the phenomenon in details.

Albert Einstein also made his own study of theBrownian motion. He published his works on this in 1905.

Later, Einstein wrote that his major aim was tofind facts that would guarantee the existence of atomsof definite size. In the midst of his work, he discoveredthat, according to atomic theory, there would have to bean observable movement of suspended microscopicparticles. Actually Einstein was correct on this. Brownianmotion results from the bombardment of the dispersedparticles by the molecules of the dispersion medium.

Between 1905 and 1911 Jean-Baptiste Perrin,a French physicist, verified Einstein�s analysis. Perrinwas even able to obtain a value for Avogadro�s constantof 6.5 x 1023 through his studies of the Brownian motion.His work established the physical theory of Brownianmotion and ended the skepticism about the existenceof atoms and molecules as actual physical entities.

THE BROWNIAN MOTION:Molecules onthe Move

1. Give examples of processes wherein the Brownian motion can be applied.

2. How did Robert Brown, the founder of the Brownian movement, discover the phenomenon?

3. Cite other scientists who made significant studies concerning Brownian motion. Explain their works briefly.

bombardment - subjecting of a substance to a stream ofhigh-speed particles

Avogadro�s constant - the number of molecules in a mole

References:

1. Microsoft Encarta Encyclopedia 99

2. Encyclopedia Britannica

3. The Encyclopedia Americana Intl Ed. 1983 Grolier Incorporated.

TTby Raymond A. Oliveros

23JUNIOR

ACTIVITY 1

Put a number of eggs into a transparent bowl of

water. An egg that will rest on its side at the bottom of

the pan is a fresh one. If it is a few days old, one end will

turn upward, and if rotten, it will float.

As the egg gets older, some of the white and

yolk lose water through the pores of the shell, and the

liquid is replaced with air. The air accumulates in the

large end of the egg, where there is an air cell.

The air is buoyant and tends to lift the egg, more

and more as the egg gets older.

ACTIVITY 2

To know if the egg is hard-boiled already, spin

the egg on its side. A hard-boiled egg will spin smoothly.

This is because the liquid inside the shell has been

hardened and turns with the shell. When a raw egg is

spun, the liquid does not spin at all with the shell, but

actually acts as a brake to stop the spinning of the

egg.

IdentifyingGood Eggs

24 JUNIOR

C R O S S W O R D1 2 3 4 7 5 6

7 5 6 8 9

10 11 12

13 3 4 14

15 16 17 8

2 18 5 7 7 19

20 21 5 22 23 24

25 5 6 26

27 4 28 29 7 30

31 32 33 8

1 3 34 7 35

1 36 6 37

ACROSS 1 virus transmitted through an animal bite 5 Strontium 7 a smaller relative of the horse 8 a fixed ratio between two values10 _ _ _ _ _ _ _ _ _ _is; a disease of the bones13 preposition14 _ _ _ _ _ _m; chemical element Ir15 having a pH of more than 718 I am20 a trigonometric function22 condensed liquid25 Ge_ _ _ _ counter; an instrument for detecting presence of radiation26 Russian ruler27 _ _ _ra; extreme28 airspeed indicator30 musical note31 the launching of a spacecraft to the moon34 p_ _ _ _ _; potassium carbonate36 _ _ _y_; in Greek mythology, a part human- part goat creature37 radiate

DOWN 1 ae_ _ _ _ _; substance used in air sprays 2 an insect 3 farewell 4 _i_l_ _ _; a cut of meat 5 not affected by passion 6 _ _ _ _mé; biodata 7 K; chemical element 9 c_ _ _ _ _ _ _; inflammation of the heart11 a fossil fuel12 a crystal used to refract light16 movement or motion (prefix, combination form)17 America19 u_ _ _ _; same as 27 across21 Eskimos� houses23 functionless24 sodium chloride28 star (prefix, combination form)29 safety and health administration32 negative response33 an electrical unit35 extraterrestrial

1 2 3

In the first issue of the BatoBalani magazine, Volume 20, (Vol. 20,Issue No. 1), an item in the MindGames section (page 24), titled �As HotAs It Gets,� poised a mental puzzle but,inadvertently, got its facts confused. Thesecond paragraph should have read:

Nicholas was assigned to dothe camp fire. While he was boilingwater in a kettle, he placed aweather thermometer to measurethe water �s temperature. To hisamazement, however, he noticedthat the water was not boiling evenwhen it had not reached the100 degrees Celsius reading...

Can you explain to Nicholaswhy?

The Editor

ERRATUM