SCIENCE OF THE DAY.

New Zealand Herald, Volume LXV, Issue 20130, 15 December 1928, Page 5 (Supplement)

SCIENCE OF THE DAY.

UNBREAKABLE' GLASS. Inventors have been trying for centuries to produco unbreakable glass, and it is now claimed that a Liverpool professor and his son, working in collaboration with an Austrian chemist, liavo discovered the secret that has baffled so many others. Tho new glass is not only unbreakable, it admits the health-giving ultra-violet rays, and can bo adapted to one hundred different uses. According to history, unbreakable glass was discovered before —in tho days of the Romans. The inventor showed a glass cup to tho Emperor Tiberius. Ho threw this cup on the floor, denting it in places, and then knocked it into shape again with a hammer. • "Does anyone know of this secret?" asked Tiberius. And when the inventor replied, " No," tho Emperor ordered him to bo put to death. Ho was afraid the unbreakablo glass might cause a slump in the valuo of gold and silver. WASHING OP TIN CANS. An examination made of unwashed cans in Now England, United States, canneries revealed bacterial counts as high as 162,000 per can. Indeed, cans just out of tho machine contained a considerable number of bacteria, although not so many as in those which had stood for somo time. In the modern process of canning, tho can with the food inside is subjected to high temperature under pressure for a considerable time. The amount of time necessary and tho temperature rcquirod have been calculated on the basis of the possible bacterial contamination. If, however, tho cans contain an unduly large number of bacteria previous to the sterilisation, it is unreasonable to expect that all of the germs will bo destroyed. For this reason, the canning industry has made a special study of the possibilities from tho unwashed can and at least one group of manufacturers, the fish canning industry of the Pacific Coast, has gone on record as advocating the use of only washed cans as an additional sanitary measure and safe-guard to the food supply. The housewife who does her own canning will realise the importance of thorough washing, indeed actual boiling, of jars

and tin cans before they are used for ] lacking purposes. This is particularly desirable when empty fruit jars are held over for use year after year. COLOURS OF SMOKE. "Why is the smoko from the cigar blue, vvliilo that from the lips is grey? Smoko consists of minute particles suspended in the air, and its colour depends upon the size as veil as chemical constitution of the particles. Highly-heated particles are. bluish in colour. Tho blue smoke, upon entering the mouth, cools, loses its smallest particles through moisture and emerges grey or brown. GASES FROM AUTOMOBILES. For the purpose of furnishing the public with authentic information concerning the subject of automobile exhaust gases and Iho danger or lack of danger resulting from the pollution of (lie atmosphere with such gases, a joint committee, has been formed in America to encourage research and investigation toward the reduction of | tho amount of carbon monoxide formed in automobile operation and to attempt to eliminate this entirely if possible. 1 his committee is constituted of delegates from ♦ ho American Automobile Association, American Chemical Society, American Medical Association, American Fetroleum Institute, American Public Health Association, Motor Truck Association of America, National Association of Taxi-cab Owners, National Safety Council; Society of Automotive Engineers, United States Bureau of Mines and United States Public Health Service. From information at hand regarding the amount of carbon monoxide to which tho public is exposed and the probable effects of such amounts, tho committee is led to 1 believe that no alarming condition exists in tho thoroughfares. However, in confined places, such as some cab stands enclosed driveways and commercial garages, tho carbon monoxide health hazard is more pronounced.The efforts oft tho committee will be directed particularly to correcting conditions that aro wrong, in such places.