346 HUMAN BIOLOGY 



with respect to several nutrient principles, so that the 

 individual is brought into a condition of chronic injury from 

 lack of one or another of the vitamins, or from an inappro- 

 priate supply of mineral elements. The most advertised 

 inorganic deficiency in recent years is that of iodine depriva- 

 tion in its relation to the development of simple goiter. 

 It is now known that a lack of sufficient iodine will result 

 in a certain type of thyroid enlargement which is very 

 common in so-called goiter areas of which there are several 

 in the United States and Canada. To offset this deficiency 

 enterprising salt manufacturers have put upon the 

 market iodized salt which is said to contain approximately 

 4 ounces of potassium iodide to a ton of salt. At the present 

 time there is some difference of opinion regarding the sound- 

 ness of the practice of offering iodine to a population in this 

 manner. The truth appears to be that almost all people in 

 goitrous districts would be benefitted by taking iodized 

 salt. On the other hand, a small number who suffer from 

 adenomatous thyroid are likely to be injured by taking 

 more than the very minimum of iodine upon which health 

 can be maintained. It is always wise, therefore, for one with 

 thyroid disease to secure the advice of a specialist concern- 

 ing the procedure to be adopted. 



A few words concerning the danger from spoiled food 

 should be added. There is considerable carelessness in the 

 household in the matter of odd remnants of food which 

 are often kept for many hours or several days in ineffective 

 refrigerators. Foods which become contaminated with certain 

 kinds of organisms are very dangerous indeed. What is 

 still frequently called "ptomaine" poisoning — a word which 

 has tended to fall into disuse in recent years, the term 

 "food poisoning" having taken its place — is in general 

 poisoning from paratyphoid infected food. It appears also 

 that other kinds of spoilage, especially that in which the 

 proteins tend to undergo decomposition, may cause severe 

 and often fatal illness. It is therefore never safe to serve 

 poorly preserved remnants of food. If any taint is suspected 

 food should be discarded, and should never be eaten except 

 after re-heating for some minutes at boiling temperature. 

 Another type of food poisoning is due to the growth of the 



