544 MICRO-ORGANISMS AND DISEASE [chap. 



contained none is absolutely certain. When such a flask 

 is placed in the incubator, after twenty-four to forty-eight 

 hours or later there are found in it large quantities of bacilli, 

 the spores of which must have entered from the air during 

 the process of preparing the infusion. The bacilli are such 

 as described by Sattler ; they soon form spores in the ustial 

 way. Such an infusion is very poisonous, just like the fresh 

 one. Sattler has shown, and this is easily confirmed, that 

 the spores of these bacilli stand boiling for a few minutes 

 without losing their power to germinate. Consequently, if 

 such a poisonous infusion full of bacilli and spores be boiled 

 for half a minute the spores are not killed ; proof for this : 

 that if with a minute dose of this spore containing boiled 

 infusion any suitable sterile nourishing material in test-tubes 

 be inoculated, and then these test-tubes be placed in the 

 incubator at 35" C, after twenty-fonr to forty-eight hours 

 the nourishing fluids are found teeming with the jequirity 

 bacilli ; but no amount of this material produces the least 

 symptom of ophthalmia. Every infusion of jequirity loses its 

 poisonous activity by boiling it a short time, i to i minute, 

 and hence the above result. 



In this respect the poisonous principle of jequirity infusion 

 comports itself similarly to the pepsin ferment, which, as is 

 well known, is destroyed by short boiling. 



If an infusion is made as above, and after fifteen minutes 

 it is filtered and then subjected to boiling for |- to i minute, 

 it will be found to have become absolutely non-poisonous, 

 but not sterile : placing it in the incubator after twenty-four to 

 forty-eight hours, vast numbers of the jequirity bacillus are 

 found in it. But no amount of this fluid is capable of 

 producing the shghtest symptom of ophthalmia. 



A large percentage of the rabbits, whose conjunctiva has 

 been inoculated with the fresh unboiled poisonous infusion. 



