immunizing sera. The latter possessed the normal antitoxic and antihacterial properties. Cobra venom, in a 1% solution, maintained in liquid air for 9 days, presented an unaltered toxicity (Lumiere and Nicolas, Province mcdicale, Sept. 21, 1901). According to Pictet (1893), pfomains were affected by exposure to temperatures of-100°t o-200°. 4. Viruses. A strain of bacteriophage active on B. coli and one active on staphylococci, frozen at-78°(with solid CO2) and thawed 20 times consecutively, did not lose any of their activity (Sanderson, 1925). D'Herelle (''The Bacteriophage and Its Behavior," p. 300, Baltimore, 1926), however, reported that while the phage (one for staphylococci and one for dysentery bacilli) was not affected in young filtrates, it was inactivated by 1 to 3 freezings in liquid air, when treated in filtrates more than 17 days old. Rivers (1927), using 19to 90-day-old filtrates of a phage lytic for B. coli, observed that, after 12 freezings in liquid air, the phage was completely inactivated when physiological salt solution was used as a diluent, and that it was partially inactivated when the diluents were Locke's 18 solution, distilled water, or hrotli, the dcni-cc ol" iiiactivatiou decreasing in the order given, lie then cxixMiincuted with dilutions of 1-10 and 1-1000 of tlie slock filtrate and found lliat an increased dilution with salt and Locke's solution increased the percentage of phage inactivated while, on the coiiti'ai'N', increased dilution with distilled water or brotii did not. According to Stockman and Minett (li)2G), the virus of foot and mouth disease was not destroyed by repeated freezing in ammonia brine. Pictet and Yung (1884) reported that the cow-pox vaccine was inactivated after two consecutive exposures of respectively 108 hours to-70°a nd 20 hours to-130°. According to Barrat (1903), an exposure of the rabies virus to the temperature of liquid air for 1 to 5 hours did not inactivate it. Salvin-Moore and Barrat (1908) found that a stay of 30 minutes in liquid air did not affect the graftable mouth cancer. Gaylord (1908) obtained identical results with the same material maintained in liquid air for 80 minutes. Rivers (1927) observed that the herpes virus in a brain emulsion was not inactivated by 12 freezings in liquid air ])ut was inactivated when frozen 24 times in an emulsion diluted 1-20 or more with Locke's solution. Similar results were obtained by the same author with vaccine virus, which resisted 12 freezings in a testicular emulsion diluted 1-10, 1-100, and 1-1000, Imt the titer of the virus decreased after 24 freezings at. dilutions of 1-10,000 and 1-100,000 and the virulence was completely destroyed after 34 freezings at a dilution of 1-100,000. Rivers investigated also rims III and found it to be readily inactivated after 12 freezings at dilutions of 1-10 of his stock emulsion. The results on the infracellulars can be summarized as follows: 1. The enzymes, toxins, bacteriophage and viruses investigated are not affected by a freezing of their 28 })osiii-(' to (lilT...