A FEW WORDS ABOUT EATABLES. 69 1 



chemical correspondence between these various substances and those 

 which are akin to them. Thus : 



Carbon. Hydrogen. Oxygen. 

 Starch ~) 



Dextrine | 



Cellulose Y 12 10 10 



Lignine or woody matters 



Gum J 



Cane sugar 12 11 11 



Grape-sugar ) 12 12 12 



Amyloid substance ) 



Lactic acid 6 6 6 



There is no difficulty, therefore, in understanding, to some extent, 

 how it is that, under the action of pepsin, or diastase, or some other 

 ferment, starch, and dextrine, and cellulose, and lignine, and gum, and 

 cane-sugar, and grape-sugar, and amyloid substance, may be trans- 

 formed into the lactic acid which forms so important an ingredient in 

 gastric juice, and that the lactic acid so formed, after having done its 

 work in digesting nitrogenous substances, may be absorbed into the 

 circulation directly, and be there disposed of in oxidization as a very 

 readily inflammable fuel perhaps as the more readily inflammable of 

 all the force-fuels. And certainly there is no reason to believe that 

 amyloid substance or sugar is more inflammable than lactic acid, but 

 rather the contrary, for lactic acid can not be traced, as amyloid 

 substance and sugar can be, beyond the limits of the alimentary canal. 

 In any case I am, I think, at liberty to assume that a good deal of starch 

 and sugar, and of the articles akin to them, are of great use in supply- 

 ing lactic acid, and that this lactic acid has to do very important 

 woi'k, not only in the primary processes of digestion, but also as force- 

 fuel. 



C. If this be so, the effect of taking sour buttermilk, sour milk, 

 and sour whey the sourness of which depends upon the presence of 

 lactic acid ought to be unequivocally beneficial in many cases. 



M. So it is. I have long been in the habit of recommending these 

 articles in cases where the digestive power is feeble and the circulation 

 wanting in vigor, and I am quite satisfied that the practice is very 

 satisfactory in its results. Instead of being " a weight to the stom- 

 ach," as fresh milk often is said to be in these cases, these drinks are 

 generally found to facilitate digestion and to keep up the warmth of 

 the system. Indeed, by using sour buttermilk and sour whey, I have 

 often found it possible to leave off doses like rum-and-milk, and to do 

 without alcoholic drinks altogether. 



C. I am prepared to believe what you say by what I know of the 

 experience of those who take sour milk or sour buttermilk habitually, 

 or who have tried the whey-cure. I have more than once heard an 

 Irish peasant say that he misses the sour milk he takes along with his 

 potatoes almost as much as the potatoes themselves, and that "it 



