to complex as the dye industry. It literally lies next our skin in the clothes w e wear. Its products are always before our eyes, in the ink with which w e write, in the stains on our furniture, in the dye on our rugs. T h i s industry, furthermore, helps to keep us well and to heal us when we are ill; its byproducts are m e a n s of national defense. It is literally an essential industry. F. M. Rowe. "Colour Index." Here u r a c t i d v all commercial dves are amanxed . in tabular form. Methods of prepaxation and properties are given in detail. Georgievics and Grandmougiu, "A Text Bwk of Dye Chemistry." This is the best . onevolume book on chemistry of dyes. J. C. Cain, "Intermediate Products for Dyes." Intermediates are well described. R. Norris Shreve. "Dyes Classified by Intermediates." A reference book for relation of dyes to intermediates.
Tells How Drugs Poison Bacteria. The synthetic drugs of modern chemotherapeutic~act as "shock troops." and the antitoxins which they induce the body to form are the "mopping-up squads" in the battle against invading bacteria. This. broadly stated, is the kernel of the theory of the action of such products of the dyestuffs laboratory as salvarsan and Bayer 205 advanced by Dr. Wilhelm Rwhl. expert of the Elberfelder Farbwerke. "The first action of chemotherapeutic substances." he said. "is directlv germs themselves. poisonins them. The auto. uoou . the. nomic production of antitoxins by the body, which the drugs induce, is of mondary imuortance but valuable for the h a l destruction of the bacteria p~eviouslydamaged by the ehemotherapeutics." The theory of the chemical action of synthetic drugs containing arsenic advanced by Dr. Paul Ehrlich, the inventor of salvarsan, best known of such arsenicals, was dip cussed by the assembled scientists. Though such drugs are of extremely wmplex chemical structure, their final action on disease germs, according to Dr. Ehrlich's view is similar to that of the common arsenic used in rough-on-rats or in the too-papular, present-day murder mysteries. The famous German scientist holds that the compiicated organic arsenic compounds act by the reduction of the arsenic acid p u p they contain to arsenic oxide. He also holds that organic drugs containing antimony, vanadium, bismuth, mercury, silver, gold, and platinum act in a similar manner.Science Senice Rubber Behaves Like Crystal When Stretched. Why does a rubber band stntch. and what haoueus . . when it does? This is the question that Dr. Paul Katz of the University of Amsterdam asked bimself, xncl partially answered at the recent meeting of the Association of Ccrman h'atural Scientistq and Physicians at Du.;zcldorf. The puzzling thing to scientists about the stretching of a rubber band is how i t can stretch so much, even twelve times its original length, without breaking, when the molecules of which it is made must hc so widely scparuted. Dr. Kntz used the X-ray spectrograph, an apparatus hy which it is possible to take photopraphs which reveal t h e act&l Langement of the molecules and the distances between them. Ordiarily, the X-ray spectrograph only works with substances that are in the form of crvstals. Rubber is not crvstalline. hut amamhaus. However, Dr. Katz tried it and has found that when the rubber is stretched, the photograph shows that it behaves just as if it were crvstalline. and returns to the amomhous form when collaosed. So far he has been unable to explain why this should occur.-Science Service
