POISONOUS ICE-CEEAM. 79 



was heated to 70° C. (158° F.) (tyrotoxicou decomposes at 

 91° C. (195.8° F.)) for some minutes, and filtered. This 

 filtrate, which was perfectly clear, was treated with'a small 

 quantity of nitric acid in order to convert the tyrotoxicon 

 iuto a nitrate, then pure potassium hydrate in the solid 

 form was added until the solution was strongly alkaline. 

 This solution was concentrated so far as it could be on the 

 water-bath. (The potassium compound of tyrotoxicon is 

 not decomposed below 130° C. (234° F.).) The dark 

 brown residue, after cooling, was examined with the micro- 

 scope and found to contain the crystalline plates of tyro- 

 toxicon-potassium hydrate, along with the prisms of potas- 

 sium nitrate. The former was separated from the latter 

 by extraction with absolute alcohol and filtration. The 

 alcohol was evaporated to dryness on the water-bath, and 

 the residue again extracted with absolute alcohol. From 

 this alcoholic solution tyrotoxicon was precipitated with 

 ether. The precipitate was decomposed by adding acetic 

 acid and heating, the tyrotoxicon being broken up into 

 nitrogen and phenol. The phenol was recognized by pre- 

 cipitation with bromine water, and by other well-known 

 tests. 



" On October 8th, the coroner's inquest, which had been 

 adjourned after the post-mortem in order to await the re- 

 sults of the analysis, was resumed, and after hearing the 

 testimony in accordance with the above stated facts, the 

 jury returned a verdict of death from poisoning with tyro- 

 toxicon." 



Camman reports twenty-three cases of milk poisoning 

 which he attributes to tyrotoxicon, although this poison 

 could not be found in the milk. It may be that the active 

 agent ])resent belongs to the bacterial proteids. 



KiNNiCUTT has isolated tyrotoxicon from milk which 

 had been kept for some hours in an unclean vessel. 



Poisonous Ice-cream. — In 1886, Vaughan and 

 NoVY obtained tyrotoxicon from a cream which had 

 seriously affected many person at Lawton, Michigan. 

 Vanilla had been used for flavoring, and it was supposed 



