MAN AND THE MICROBE 13 



epidemics which have affected the patrons of dairies where every possi- 

 ble precaution was taken shows that no raw milk can be considered a 

 safe food. For infants, breast milk is the only proper nutriment, but 

 for babies who can not possibly receive a mother's care, and for older 

 children and adults, we have fortunately a simple and efficient protec- 

 tion in pasteurization. This process, which involves simply the heating 

 of the milk to a temperature of 145° or thereabouts for a period of 

 twenty minutes, represents the application of the saving grace of cook- 

 ery to the food product which of all food products needs it most. Un- 

 like scalding or boiling pasteurization does not alter the taste of milk, 

 and one of the most effective ways of guarding the household against 

 disease is to see that all milk which enters it is properly pasteurized. 

 There is no more excuse for drinking raw cow's milk than for eating raw 

 beef. 



A third danger, but far less important than those inherent in water 

 or milk, lies in the consumption of raw shellfish which have been grown, 

 or more commonly fattened (swelled up and made to seem more plump 

 by immersion for a time in brackish water), in tidal estuaries exposed 

 to sewage pollution. Fortunately it appears that during the winter 

 months oysters, at least, enter into a state of practical hibernation, clos- 

 ing their shells and taking in little water from outside. Under Buch 

 conditions sewage bacteria, already present within the shell, soon die 

 out and the oyster even when taken from polluted waters becomes a 

 comparatively safe source of food. Most of the famous epidemics of 

 typhoid fever caused by shellfish have occurred in the months from 

 September to November, after the eating of raw shellfish begins and 

 before hibernation has set in. The eating of raw or partially cooked 

 shellfish (steamed clams, fried oysters, oyster stew) from unknown 

 sources, particularly in the autumn months, is, however, a dangerous 

 practise until the oyster industry is more thoroughly supervised than 

 at present. 



Finally, in connection with the transmission of disease by food, the 

 danger of infection of any and all foods in the process of preparation 

 should always be kept in view. If for example, sandwiches are pre- 

 pared by a typhoid carrier, an epidemic is likely to result, as was the 

 case recently in a town of Illinois. I have referred to Mary Mallon, 

 our mOst famous American case of the carrier in the kitchen. After 

 a brief incarceration by the New York City Health department, 

 this woman was set free and she may now under another name be 

 cooking for some one of the readers of this article. Not only water 

 and milk and shellfish, but meats and vegetables and bread and forks 

 and spoons and tumblers may be infected by a cook or a waitress who 

 is a carrier, and many obscure cases of disease are traceable to this 

 cause. The tragedy of such an occurrence was once personally brought 

 home to me with keenness by the death of one of the most promising 



