404 THE POPULAR SCIENCE MONTHLY 



largely depended upon to render harmless any disease-producing germs 

 that may be contained in our food. While this is true of bacteria it is 

 not true of all the products formed by them. Certain ptomaines and 

 toxins may be destroyed by heat. Others are not susceptible to its influ- 

 ence. Therefore heat as employed in the process of cooking can not be 

 regarded as a safeguard against ptomaine poisoning. Moreover it is 

 often after cooking that these poisons are formed. Many of our cooked 

 foods constitute the very best kind of culture media and as a result 

 putrefactive changes may take place in them very rapidly. The safe 

 plan is therefore to eat food soon after cooking or if it is reserved for 

 any length of time it should be well protected from bacterial invasion 

 and kept at a low temperature. 



Cleanliness and low temperature afford the best means at our com- 

 mand for preserving foods from bacterial action — cleanliness to prevent 

 the presence and contaminating influence of the millions of bacteria, 

 often of the putrefactive type, which are always to be found where dirt 

 and filth of any kind is allowed to accumulate and where flies and other 

 insects are given free access, and low temperature to prevent the multi- 

 plication of those already in the food, no matter how careful we may 

 have been to exclude them. Cold, even a freezing temperature, is not 

 fatal to bacteria, but it does decidedly retard their growth. Even at 

 the temperature of the ordinary refrigerator (about 10° C. or 40° P.) 

 we find that most organisms multiply very slowly and as a result putre- 

 factive changes are much retarded. Refrigeration is therefore a neces- 

 sity for the proper keeping of foods, at least during the hot season. But 

 to be efficient the refrigerator must be properly managed. Unless it be 

 kept clean, properly ventilated and well supplied with ice it is practically 

 useless, in fact absolutely dangerous. 



Public sentiment is now demanding that those who produce and 

 handle our foods should furnish them to us in a pure and wholesome 

 condition and sanitary officials on every hand are endeavoring to en- 

 force the proper regulation and protection of our food supply. This 

 effort is most commendable. It is well to remember, however, that 

 official regulation can extend only to our doors and to be fully effective 

 it must be supplemented by proper management in our homes and in all 

 places where food is consumed. 



In conclusion, we must admit that well-defined cases of ptomaine 

 poisoning are comparatively of rare occurrence when we consider the 

 amount of food consumed and the number of consumers. They would 

 indeed be exceedingly rare if those who are charged with the prepara- 

 tion and handling of our foods would always exercise the proper pre- 

 cautions along the lines we have indicated. 



