86 Dairy Bacteriology. 



Many of the cases of poisoning due to ice cream, cheese, 

 and milk come from such a source. Improperly handled 

 milk may be made up into these various products, and 

 in this condition, the poisonous principle remain un- 

 changed for a considerable time. Vaughan 1 has isolated 

 a poisonous substance from these materials, calling it 

 tyrotoxicon (cheese poison). Our knowledge concerning 

 the way in which it is produced is, as yet, very vague, 

 but from his most recent researches 2 , it is quite probable 

 that the organisms causing these troubles are putrefac- 

 tive forms that gain access to the milk where it is im- 

 properly kept. 



1 Vaughan, 9th Intern. Hyg. Cong., (London), p. 118, 1891. 



2 Vaughan and Perkins, Arch. f. Hyg., 27: 308. 



