THE HYGIENE OF NUTRITION 357 



These persons are depressed or morose, often querulous 

 and prejudiced, seeming to be their own worst enemies. 

 The contrast which they present with the overfed is a 

 consistent one. The man who eats too much and 

 escapes indigestion is usually overweight, florid, not 

 very diligent, a heavy sleeper, and an optimist. There 

 are drawbacks in either case. The picture of the 

 underfed subject is much the same whether his habit 

 is the result of outward circumstances or alimentary 

 incapacity. 



Food Poisoning. We must indicate a distinction be- 

 tween auto-intoxication which is due to the production 

 of poisons in the canal and the acute attacks which 

 may be occasioned by food that has become poisonous 

 before it is eaten. Such changes in food are fortunately 

 rare. We need to reflect that very extensive decom- 

 position may occur without making food dangerous. 

 The supreme examples are furnished by certain cheeses 

 which have been so treated as to advance putrefaction 

 to the utmost. They rarely cause sickness. 



From time to time we hear of outbreaks described as 

 ptomain poisoning. They are undoubtedly less frequent 

 than they were thirty years ago, for greater intelligence 

 in regard to the control and inspection of food has had 

 a favorable effect. A ptomain is defined as a bacterial 

 product derived from nitrogenous food. It is usually 

 assumed to be rather simple in its chemical nature and 

 has been described as an animal alkaloid. This is not 

 a good term for we can probably obtain the same 

 ptomains from vegetable proteins as from those of meat. 

 The word ptomain need not of necessity suggest a poison, 

 but it is usually so understood for, among many com- 

 pounds released simultaneously in certain types of de- 

 composition, there are some which are intensely toxic. 



Meat and fish, including shellfish, have figured in 

 most of the spectacular cases. A number of persons 

 who have eaten food from a common source, it may be 

 at a banquet, have become violently ill. A few hours 



