BACTERIA IN FOODS 2O$ 



Before passing on to other matters, reference must be 

 made to poisonous products other than bacteria which 

 occur in milk and set up ill-health. Vaughan, of Michigan, 

 pointed out at the London Congress of Hygiene in 1891 

 that he had separated a poisonous alkaloid, which he called 

 tyrotoxicon. This, as its name denotes, was a toxic or 

 poisonous substance, probably produced by some form of 

 microbe. It may be taken as a type of the organic chemi- 

 cal substances frequently occurring in milk. 



METHODS OF PRESERVING MILK 



From the somewhat extensive category of diseases which 

 may be milk-borne, it will be suitable now to speak of some 

 of the means at our disposal for obtaining and preserving 

 good, pure milk. 



We considered at the commencement of this chapter the 

 most frequent channels of contamination. If these be 

 avoided or prevented, and if the milk be derived from cows 

 in good health and well kept, the risk of infection is re- 

 duced to a minimum. But we have seen that much, if not 

 most, of the pollution of milk arises after the milking pro- 

 cess and during transit and storage preparatory to use. 

 Bacteria are so ubiquitous that to prevent the entrance of 

 any at all is almost beyond hope. Can anything be done to 

 prevent their multiplication or to kill them in the milk ? 

 Fortunately the answer is in the affirmative. 



There are two means at hand to secure these results. 

 First, we may add to the milk various chemical or physical 

 preservatives. Borax or boric acid, formaldehyde, salicylic 

 acid, and other chemical bodies are used for this purpose. 

 The commonest of these is that named first. The Food 

 and Drugs Act (Section VI., 1875) permits the addition of 

 an ingredient not injurious to health if the same is required 

 for protection or preparation of the article in question. It 



UNIVERSITY 



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