68 SCIENCE AND PRACTICE OF CHEESE-MAKING 



to which it is fed, especially when fed alone and 

 in excess. There is another even more important 

 reason why whey should be pasteurized. The 

 whey-vat has been known to become a distributing 

 source of disease among calves and pigs and of ab- 

 normal fermentations that injure the quality of cheese. 

 Sweet whey has a value of 6 or 7 cents per 100 pounds 

 when sold for the manufacture of milk-sugar, but com- 

 paratively little whey can be actually disposed of in 

 this way. 



CHEESE POISON 



For a long time it was known that cheese some- 

 times acts as a violent poison, but it was not until 

 about 25 years ago that a specific poisonous com- 

 pound was isolated from cheese. Many cases of 

 cheese poisoning had occurred in Michigan at the 

 time and the matter was investigated by Dr. V. C. 

 Vaughan, professor of physiological chemistry at 

 the University of Michigan, who succeeded in sepa- 

 rating from some of the poisonous cheese an in- 

 tensely poisonous compound, which he called tyro- 

 toxicon (cheese poison). The poison is present in 

 cheese in only very minute amounts, but is intensely 

 powerful. A drop of a highly dilute solution of this 

 poison placed on the tongue produces a characteristic 

 benumbing sensation. This poison is the result of 

 bacterial action and is produced only by those bacteria 

 which are associated with conditions of filth. There 

 are sometimes also other poisons in cheese, less well 

 known. 



