VOL.9. No. 12
SOME ASPECTS OF CATALYSIS
2031
formation ( a n autocatalytic catalyst) would h a v e to be considered as being aliue, at least potentially. T h e smallest living units we now know, genes a n d t h e smaller ultrafiltrable "viruses," approximate t h e size of large molecules or small molecular groups. In addition to t h e power of selfduplication o r autocatalysis, t h e y also possess the power of directing other, a n d generally m a n y other, chemical changes. Within each chromosome which t h e microscope reveals i n e v e r y germ cell, lie a multitude of genes, those highly specific, exceedingly small catalytic and autocatalytic units which determine into w h a t t h e germ will develop, given suitable environmentrose or a sunflower, a mouse or an elephant. Viewed as carriers of heredity, gene catalysts constitute t h e most precious substance i n t h e world.
FEDERAL CHEMISTS SHOW HOW ACIDS DAMAGE PAPER Adds, even in minute quantities, cause papers to "age" and deteriorate so that they crack when folded. To libraries and to governmental and business offices which must preserve written and printed records for long periods, this aging of papers has been a problem of importance never satisfactorily solved. Federal chemists have demonstrated that hydrochloric acid and sulfuric acid causc the deterioration of paper. When chlorine compounds are used in bleaching paper pulp hydrochloric acid may form in the finished product unless the pulp is washed clean. Aluminum sulfate is generally used in sizing paper and if present in excessive quantities will causc deterioration of the finished product. Tests by workers in the Bureau of Chemistry and Soils, Washington. D. C., show that no matter how carefully made or how rood the original fibers may he, the paper must be virtually free from acid or it will not endurc For permancncc excess chemicals should be washed out of the paper pulp and only the minimum quantity of alum should be used in sizing. Acid in paper h a long been suspected of causing deterioration, but little systematic work has bccn donc to prove the harmful effect of mineral acids. These investigations by T. D. Jarrell, J. M. Hankins, and F. P. Veitch of the U. S. Department of Agriculture included tests of strong unsizcd all-rag bond paper. This papcr showed practically no decrease in strength after being artificially aged by heat for 336 hours a t a temperature of 100°C. Varying small quantities of aluminum sulfate, sulfuric acid, and hydrochloric acid, respectively, werc incorporated in the paper which was then artificially aged by heating for 72 hours a t 100'C. (the temperature of boiling water). Tests of folding endurance, bursting strength, and tensile strength tests showed that of the three chemicals hydrochloric acid was the most destructive, as little as 0.029 per cent. acid in the paper causing 22 per cent. loss in folding endurance. and 0.040 per cent, causing a loss in folding endurance of nearly 100 per cent. Sulfuric acid present in as small quantities as 0.033 per cent. caused about 19 per ccnt, loss in strength as measured by folding endurance, while 0.074 per cent. decreased the strength ahont 99 per cent. Aluminum sulfate had practically the same eRcct as sulfuric acid when the activc acidities were the same.
