PTOMAINE POISONING 201 



know that strictly fresh foods never contain these poisons. 

 We know that their development is dependent in a measure 

 upon temperature, inasmuch as they do not develop in food 

 that is kept cool. We know that decomposition products 

 are more likely to give rise to poisonous ptomaines in the 

 absence of oxygen than in its presence. We know, lastly, 

 that injurious substances are produced by bacteria ; but 

 we do not yet know the source of the bacteria, nor have 

 we, for this reason, discovered any methods for keeping 

 them from our foods other than those ordinarily adopted 

 for checking bacterial growth. Anything that will pre- 

 vent bacteria from growing will prevent ptomaine poison- 

 ing. Consequently low temperature, drying of foods, and 

 the other devices already suggested are the only means we 

 have for guarding ourselves from such troubles. We may 

 wisely remember that ptomaine poisoning is most likely 

 to occur in foods that have been kept for some time in a 

 moderately warm temperature. Fresh foods never contain 

 poisonous ptomaines. 



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 prevent- 

 ing 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, and be particularly 

 careful to consume quickly any material taken from cold 

 storage. When food begins to have the smell of decom- 

 position, it becomes suspicious, although this does not 

 mean that it is necessarily dangerous, since many of these 

 decomposition products are quite harmless. The food 

 product that seems to give the largest amount of trouble is 



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