CHAPTER XXXV. 

 PRESERVATION OF FOOD. 



WHERE a race is dependent upon a local or seasonal supply of 

 food it occurs that in one district or during one season there is an 

 abundance, whereas in another locality or at another season there 

 may be a scarcity which at times amounts to a famine. This state 

 of affairs was very common in the earlier history of the race, but 

 modern methods of transportation and food preservation has made 

 it possible for the modern individual to have a sufficient and varied 

 diet at all seasons. A varied diet is more certain to contain all those 

 constituents which are essential to the body needs than is a restricted 

 or monotonous diet. Moreover, it is well recognized today that 

 nutritional disorders are more likely to occur on a restricted than on 

 a varied diet. Hence, the general result of the expansion in the 

 kinds of food consumed is good, but the food should be preserved 

 in a manner such that as little as possible of the nutrient constituents 

 are lost; so there is little change in appearance and taste and nothing 

 is added nor developed in the food which is deleterious to health. 



Heat, cold, drying, and the use of some chemicals have long been 

 in use for the preservation of food, but it is only recently that the 

 art has been developed to its highest perfection. This is due to the 

 fact that the art of food-preserving depends upon the science of 

 bacteriology, and today it is possible to preserve some foods indefi- 

 nitely without injuring their nutritive value or seriously interfering 

 with their taste and appearance, and all such methods are legitimate. 



But "the chief harm has come from the blind use of chemical 

 germicides without regard for their harmful properties. The 

 simplest and cheapest way to preserve food is by adding one of these 

 chemicals and the method was, therefore, seized upon by alert men 

 whose chief interest was of the pecuniary kind. The question was 

 to find the smallest percentage of a chemical which would prevent the 

 decay of some particular food product, trusting to luck that the 

 preservative used would prove harmless to the consumer. Often 

 these chemicals were added with a liberal hand ; further, it was soon 

 found that chemical preservatives could be used to preserve food 

 products for the market from materials already so decayed as to be 

 unsalable in their original condition." 



Methods of Preserving Foods. Methods of preserving foods may 

 be roughly classified as follows: 



