344 MICRO-ORGANISMS IN WATER 



capillary tube was transferred to a test tube containing 

 sterile bouillon ; both of these were then removed to the 

 incubator and cultivated at 37 C. It was found that 

 the spores in those tubes in which air was present had 

 been destroyed according to the length of time they 

 had been insolated, the period-* varying between 29, 

 30, and in one case 54 hours. On the other hand, the 

 spores which had been insolated in the liquid sealed up 

 in the capillary tubes (therefore in the absence of air) 

 were found capable of germination even after 83 hours' 

 exposure to the sun. In these experiments Eoux took 

 the special precaution of exposing the spores in the very 

 medium in which they had been produced, precluding, 

 therefore, the possibility of their germination into ba- 

 cilli in this exhausted material. In other experiments 

 bouillon 1 infected with anthrax spores was insolated, 

 in some of the tubes air was excluded, whilst in 

 others air was allowed to gain access. On the com- 

 pletion of the insolation both the aerobic and anaerobic 

 tubes were placed in the incubator ; in the case of the 

 latter the contents were poured into an empty vessel 

 to which air had access. It was found that whilst the 

 spores which had been insolated in the absence of air 

 were able to germinate even in the same bouillon in 

 which they had been insolated, those spores which had 

 been insolated in the presence of air were unable to 

 germinate. Thus, in Eoux's experiments the spores of 

 anthrax were not destroyed with the same promptitude 

 as in Arloing's. On the other hand we are introduced 

 to a fresh problem, which had already, however, re- 

 ceived considerable attention from Downes and Blunt, 

 i.e., the behaviour of insolated spores in the presence 

 or absence of air. Eoux shows very clearly that they 



1 Veal-broth, slightly alkaline and very faint in colour, consisting of 

 1 part of meat to 2 parts of water. 



