88 Journal of Agricultural Research voi. iv, no. r 



As a part of experiment 32, plates were made from the material scraped 

 off the pieces of hide. In every instance the plates made from material 

 treated by 2 per cent of hydrochloric acid and 10 per cent of sodium 

 chlorid were sterile. On the other hand, growth was observ^ed on all the 

 plates from material exposed to mercuric chlorid and formic acid. 



In this experiment, as in several of the last few experiments described 

 in the previous discussion of the Seymour- Jones method, it will be noted 

 that material from pieces of hide exposed to mercuric chlorid and formic 

 acid and treated shortly after completion of the disinfection with sodium 

 sulphid failed to kill guinea pigs into which it was inoculated. On the 

 other hand, material from pieces of hide allowed to stand for several 

 days before using sodium sulphid caused guinea pigs to die from anthrax. 

 It was noted that the depilatory action of the sodium sulphid was far 

 more complete in the case of the pieces of hide which had been kept for 

 several days after disinfection before treatment with the sulphid. The 

 results of plating, as before mentioned, showed that disinfection was not 

 complete ; therefore it seems probable that the more extensive depilatory 

 action of the sodium sulphid upon pieces which had stood for some time 

 brought up from the depths of the hair follicles spores which had been 

 practically untouched by the disinfectant. It also seems possible that 

 there had been some development and multiplication of these uninjured 

 organisms during the period of waiting. 



It should be noted that in the preparation of the pieces of hide used in 

 all the above-mentioned experiments particular care was taken to secure 

 penetration of the spores into the pieces of hide. In order to accomplish 

 this, the pieces of hide after being infected by spore suspensions were 

 placed in closed Petri dishes and kept in the ice box for four or five 

 hours before the drying process was begun. 



As will be seen by reference to Table XIII, the Schattenfroh method 

 was entirely successful in every instance, and the results of plating 

 showed that actual sterilization was accomplished. 



Experiment 33 (Table XIV) was exactly similar to the preceding ex- 

 periment except that the pieces of hide used were infected by spores 

 derived from a different culture. The method of preparation was the 

 same as that described under experiment 31. 



In this experiment, as in the preceding one, the efficiency of the disin- 

 fectants was tested by plating out material from the pieces of hide. The 

 results obtained varied from the results of experiment 32 in that a few 

 colonies were found on two plates from material treated with hydro- 

 chloric acid and salt, while all other plates from similar material were 

 sterile. One plate from material neutralized by 0.5 per cent of potas- 

 sium hydrate showed two colonies, while the other, from material neu- 

 tralized by sodium carbonate, showed one colony. In none of the three 

 was Bacillus anthracis the organism present. Therefore, although hydro- 



