17 



times in serum diluted 1-100 with physiological salt solu- 

 tion (Rivers, 1927). 



Com pi cm cut, as well as awhocepter, in rabbit serum 

 immersed in liquid air for times varying from 10 to 30 

 minutes, kept their unaltered activity, according to Liidke 

 (1905). 



Tetsuda (1912) also reported that complement and 

 antihodies were not affected by maintaining the sera for 

 several days in liquid air. 



A 24 hour-old broth culture of Eberth bacilli, maintained 

 frozen in liquid air for 20 minutes, did not lose its 

 agglutinaUUty. Sheep serum, frozen in the same manner, 

 was as efficient in agglutinating these bacilli after the 

 freezing as before (Chanoz, Courmont and Doyon, 1900). 

 Macfadyen (1902a) used the juices extracted from 

 the Eberth bacilli by trituration in liquid air, to produce 

 immunizing sera. The latter possessed the normal anti- 

 toxic 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° to - 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 19- to 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 



