1 DON'T LIKE TO ADMIT IT, BUT I MISSED PlPET CLASS IN SCHOOL
SO MY PIPETS ARE ALWAYS MESSIER THAN ANYONE
TO HIDE IT, I USED TO BREAK THEM AND BLAME IT ON THE WASHERS
THEN CORNING INVENTED SUPERSTRONG COREX BRAND PIPETS THAT LAST THROUGH SIX TIMES THE WASHINGS
AND THEN THEY LOWERED PRICES UP TO 4 0 * ON THE D0LIAR,S0 EVERYONE CAN USE THEM
ANO NOW THEY'RE EVEN PERSONALIZING MY PtPETS SO I CAN'T SWITCH BASKETS
EVERY MOMTH I CHANGE MY NAME, JUST FOR SPITE.
ELSE'S
Put your name on the strongest pipetyou can buy—superstrength COREX® brand pipets from Corning. They're available now at new, low prices. Call your Corning dealer for complete details.
CORNING LABORATORY PRODUCTS M a k e r s of PYREX® Labware Circle No. 180 on Readers' Service Card
26A · ANALYTICAL CHEMISTRY
Report weaker t h a n t h a t noted with croton oil and its purification products. When we move to the area of air pollution, we observe a family of compounds containing both initiators and promoters, such as phenols of unknown constitution, the question of their direct role remains open (31). There is however, no question that the cigarette smokers or urban populations exposed to automobile exhaust products have a significantly higher rate of lung cancer, but the correlation of all the different kind of exposures in relation to production of cancer remains extremely difficult. T h e situation is clearer when we have a starting point, for example, with uranium miners or chromium workers where the product of the radioactive metal radon, or the chromium metal are the obvious prime suspects (32). However, all the other known agents which increase lung cancer in the rest of the population serve to confuse the picture. For example, the smoking miner has twenty times the incidence of lung cancer t h a n his nonsmoking coworker (32). The air we breathe, contaminated with cigarette smoke or not, is clearly not the only source of carcinogens ; the food we eat and the drugs we take m a y make a sizable contribution. Prominent among the materials under suspicion are the aflatoxins, which appear to be the active carcinogens present in certain batches of peanut meal fed to a variety of domestic animals (33, 34). The chemical appears to arise from a fungus growing on the nut and is, perhaps, the most studied of the larger group of plant carcinogens which includes the cycasins, extracts of braken fern and extracts from a variety of fungi (3537). Aflotoxin Blt a liver carcinogen in rat, combines with D N A , reducing its priming activity with R N A polymerase; it fits well into the category of initiating chemicals described above. T h e cycasins are naturally occurring nitroso amines and appear to be metabolized to a proximal carcinogen methylazoxymethanol. Thus, the properties of these naturally occurring carcinogens are similar to those introduced by man.
