Document zoG636n2LJZzL4KmL8Bj7dzKm

FILE NAME: Newspaper & Magazine Articles (NMA) DATE: 1964 Dec DOC#: NMA018 DOCUMENT DESCRIPTION: Scientific American - Dangerous Dust? ASCMIEENRTICIFAICN Established 1845 December 1964 Volume 211 Number 6 ARTICLES 27 H U R R I C A N E M O D I F I C A T I O N , b y 11. 11. S i m p s o n a n d J o a n n e S . M a l k n s Seeding of key clouds may set off a chain of events reducing the force of a storm. 38 TH E GEO LO GY OF TH E MOON, by Eugene M. Shoem aker Stratigraphy, applied with new techniques, gives a time scale of lunar events. 48 TH REE-PIG M EN T COLOR VISION, by Edw ard F. MaeNiehol, Jr. A study of individual retinal cells suggests the mechanism of color discrimination. 8 P R O T E I N - D I G E S T I N G E N Z Y M E S , l>y H a n s N e u r a l h Examination of their molecular structure yields clues about bos/ all enzymes work. 80 FLUID CONTROL DEVICES, by Stanley W . Augrist In some instances they do amplifying and switching better than electronic devices. 90 T H E H O P E W E L L L I L T , by O la i II. P rn le r A rubbish heap in Ohio is yielding answers to questions about Indian customs. 106 H O W C E L L S M A K E A N TIBO D IES, by G. J. V. N ossal Experiments with single cells suggest that the genes direct antibody manufacture. 116 Q U A N TIZE D V O R T E X RIN G S IN S L P E R F L L ID H ELIU M , by F. K eif They resemble smoke rings and show discrete quantum effects on a large scale. DEPARTMENTS 8 LETTERS 14 50 & 100 YEARS AGO 20 THE AUTHORS 60 SCIENCE AND THE CITIZEN 124 MATHEMATICAL GAMES 134 THE AMATEUR SCIENTIST 143 BOOKS 150 ANNUAL INDEX 154 BIBLIOGRAPHY BOARD O F EDITORS Gerard Piel (Publisher), Dennis Flanagan (Editor), Francis Bello (Associate Editor), Frederick II. Gardner, James R. Newman, John Purcell, James T. Rogers, Armand Schwab, Jr., C. L. Stong, |oseph Wisuovsky ART D EP A RT MENT PRODUCTION DEPARTMENT Jerome Snyder (Art Director), Samuel L. Howard (Assistant Art Director), Joan Starwood Gerald Meyerson (Production Manager), Richard Sasso (Assistant Production Manager) C O P Y D E P A R T M E N T Sally Porter Jenks (Copy Chief), Dorothy Bates, Julio E. Xavier 1 G E N E R A L M A N A G E R Donald H. Miller, Jr. | A D V E R T I S 1 N G M A N A G E R Martin M. Davidson B A S S I S T A N T T O T H E P U B L I S H E R Stephen M. Fischer PU B U S N E O M O N T H LY BY S C IE N T IF I C A M E R IC A N , I N C ., 415 M A D IS O N A V E N U E , N E W Y O R K, N .Y . 10017. C O P Y R IG H T 1964 BY S C IE N T IF IC A M E R IC A N . INC. A L L R IG H T S RESERVED . S EC O N D - C LA S S P O ST A G E P A ID AT N E W Y O R K , N .Y ., A N D AT A D D IT IO N A L M A IL IN G O F F IC E S . A U T H O R IZ E D A S SECONO-CLA.SS M A IL BY THE POST O F F IC E D EPART M EN T , O T T A W A , C A N A D A , A N D FO R PA Y M E N T O F P O ST A G E IN C A S H . S U B S C R IP T IO N RATE: $7 PER T EAR. TMI Tubing Stays On The pins, completely oxidized but apparent ly made of copper. Two of them, each half an inch long and a sixteenth of an inch in diameter, were pointed at one end; the third was pointed at both ends and bent at more than a right angle. Making such shapes as these from na tive copper woidd require cold-hammer ing, a technique only a few steps removed from full metallurgy. The dis coverers are now awaiting laboratory analyses to determine if the three pins are indeed copper. If such is the case, Miss (.iambel and Braidwood point out, it will prove that 9,000 years ago the people of Cayonu were "using metal as metal rather than as another object such as stone and wood." Dangerous Dust? \ * TM I adopted one of business' most challenging axioms years ago: " Think big about little things" ! By doing so, TMI tubing has developed the dependable habit of helping our customers improve their profit pat terns . . . and their product performances. It takes plenty of TM I experienced research and cold-drawing ingenuity to set such a leadership pace but it's worth it! " Little" things in quality methods spell out the " Big" difference that keeps TMI tubing on the progress beam in aerospace and nuclear applications, in instrumentation, and at every important point on the metalworking horizon. Stay on the Progress Beam with TMI. The standard range of quality production at TMI--.050" to 1.250" O.D. in colddrawnseamless and Welded Stainless, high temperatures and high corrosion alloys including Haynes, and Huntington alloys. TUBE METHODS INC. METALLURGISTS * ENGINEERS MANUFACTURER^ BRIDGEPORT (Montgomery Cot/nty), PA. I Aust consisting of fine fibers of asbes1 ^ tos, which are insoluble and virtu ally indestructible, may become a pub lic health problem in the near future. At a recent international conference on the biological effects of asbestos sponsored by the New York Academy of Sciences, participants pointed out on the one hand that workers exposed to asbestos dust are prone in later life to develop lung cancer, and on the other hand that the use of this family of fibrous silicate compounds has expanded enormously during the past few decades. A labora tory curiosity 100 years ago, asbestos today is a major component of such building materials as shingles and roof ing papers, floor tiles, insulation, wallboard and piping and is an important ingredient in such products as gaskets, brake linings and calking compounds. World production of asbestos in 1962 exceeded three million tons, and indus tries in the U.S. consumed 25 percent of the total. One result of this increasing use is that asbestos dust is frequently encoun tered in ordinary daily life. J. G. Thomson of the University of Cape Town Medical School in South Africa reported to the conference on 500 con secutive autopsies performed in Cape Town and 500 in Miami, Fla., on in dividuals over the age of 15. Smears were taken from the bottom of the lungs; in both South Africa and the U.S. characteristic "asbestos bodies" were found in 20 percent of the females and 30 percent of the males. Some of the males showed asbestos bodies in such abundance that occupational ex posure to asbestos dust appeared prob able; in 80 percent ol all positive cases, however, the incidence was low enough to suggest that the asbestos bodies were present as a result of general atmo- I spheric contamination. It is not clear what the tumorproducing factor in asbestos is. Of the ! three asbestos silicates in general indus trial use, two contain traces of iron and the third has relatively high concentrations of nickel and chromium. All three metals arc known to be carcinogenically active. Two of the asbestos minerals contain appreciable amounts of natural hydrocarbons, some of which are also carcinogenic. The Opossum as a Player An opossum playing possum is genu- J ' indy feigning death, three re searchers at the Children's Hospital of Los Angeles have decided on the basis of electroencephalograph records. The "opossum state" is well established in American folklore. Under attack the little marsupial suddenly slumps into a motionless ball with its head down, its mouth open and its eyes fixed in a glassy stare. Such behavior obviously functions as a defense mechanism: seeming to be dead, the animal is left for dead, and it revives when the coast is clear. There has been some doubt, however, whether the opossum is actu ally feigning death or is in an involun tary cataleptic state induced by physio logical changes caused by the attack. Allen C. and George Norton, Anthony A. Misrahy report iVn. StBaetnuirne that they implanted electrodes on the skulls of 15 opossums (Didelphis vir- gitdana). They induced the opossum state in these animals bv shaking them with an "artificial dog jaw," a device resem bling a large pair of pliers, and at the same time playing recorded barking sounds through a loudspeaker. When first attacked, an opossum would hiss and growl and try ter fight back at the jaw, but then suddenly all activity would cease and the animal seemed to be dead for as lung as two or three minutes. Electroencephalograph records taken before, during and after the artifi cially induced opossum state showed no change except perhaps a heightened arousal level caused by the attack and persisting after revival. To simulate the natural situation more closely the ex perimenters allowed real dogs to shake "nave" animals into an opossum state that lasted five or six minutes. Again there was no difference in the brain waves during the state and after recov ery. Finding no evidence of unusual brain activity, the investigators con cluded that "the folklore is correct; the animal is merely `playing possum.' " 64