SALT AND ITS PHYSIOLOGICAL USES. 565 



II. 



There is, then, a weli-established relation between a vegetable diet 

 and the need for .suit and reciprocally between an animal diet and the 

 exclusion of this article from food. We must now push the matter 

 further and ask the reason for these remarkable relations. This is the 

 >roblem formulated by G. Bunge, who, as a chemist, has advanced a 

 very ingenious theory for its solution. 



The answer might be very easy. If, for example, the difference 

 between the two diets was that of a difference in the amount of salt 

 which they respectively contained; if the food of vegetable origin was 

 poor in common salt and that of animal origin rich in that substance, 

 the solution would be clear; the law empirically established by Bunge 

 would have a very evident explanation. 



But the matter is not so simple. The two kinds of diet are not distin- 

 guished from each other by the quantity of salt which they contribute 

 to the organism. In fact, both kinds are very poor in salt. 



If we examine food as it comes from plants or animals we find that 

 the greater part of it is tasteless and insipid, insufficiently salted for 

 our taste. The albuminoids of meat, the fats, the starch of cereals and 

 leguminous plants, do not, by themselves alone, exercise any action 

 upon our gustative sense. The flavor of our food comes from second- 

 ary products, from aromatics and odors that are added in some way; 

 to be exact, from foreign substances existing in very minute quan- 

 tities, ethers, acids, and essential oils that culinary preparation and 

 cooking only develop to a greater degree. In general, natural food is 

 but slightly saline. 



Since the small quantity of common salt contained in natural aliments 

 suffices for our needs when the diet is confined to animal food, it ought 

 to answer for them in the case of a vegetable diet. Why is it other- 

 wise? Whence comes it that one of these methods of alimentation 

 requires the artificial addition of salt? Chemists have ascribed the 

 cause of this peculiarity to the different composition of the two kinds 

 of food. Although both contain equally small quantities of chloride 

 of sodium, they are distinguished from each other by another mineral 

 product which they possess in an unequal though considerable degree. 

 This is potash. In marked contrast with common salt, this substance, 

 always abundant, varies very greatly in its relative quantity in different 

 kinds of food. There are foods that contain a great deal of it, and 

 these are precisely those that are taken from the vegetable kingdom. 

 Plants are generally distinguished by their richness in potassic salts. 

 They accumulate enormous quantities of them, drawing them from the 

 poorest soils. Indeed, before the discovery of the mines of Stassfurt, 

 the incineration of green plants was the only source of industrial pot- 

 ash. Inversely, there are other aliments derived from animals that 



