BACTERIAL POISONS 227 



The use of fresh foods and the preservation at low tem- 

 peratures of any food that must be kept for some time are 

 the only rules that can be given at present for preventing 

 such instances of poisoning. Eat food fresh when possible ; 

 keep it cold if it must be preserved ; do not keep it any 

 longer than necessary. When food begins to have the smell 

 of decomposition it becomes open to suspicion, although 

 this does not mean that it is necessarily dangerous, since 

 many of these decomposition products are quite harmless. 

 The food products that seem to give the largest amount of 

 trouble are ice cream and fish, and it is therefore desirable 

 to be particularly on one's guard about their use in warm 

 weather and, if possible, to use only that which is fresh or 

 has been made from fresh materials. Since the dangers are 

 greatest in summer, we should be particularly careful at 

 this season not to allow any putrescible food to be warmed 

 by the sun or by standing near a stove. 



