690 THE POPULAR SCIENCE MONTHLY. 



of caseine called legumine ; rice and potato contain as little as about 

 eight per cent of nitrogenous matter, and as much as eighty per cent 

 of starch, the amount of nitrogenous matter and starch in these arti- 

 cles of food being in an inverse ratio to each other. Fatty matter is 

 especially abundant in oats and maize. It is evident, therefore, that 

 there is much in these vegetable articles of food which may take the 

 place of the nitrogenous and oily articles which are supplied in ani- 

 mal food. 



There is no essential difference as to chemical composition between 

 vegetable albumen, and fibrine, and legumine, and oily matters, and 

 animal albumen, and fibrine, and caseine, and oily matters ; there is 

 no perceptible difference in the albuminose or peptone into which the 

 vegetable and animal nitrogenous substances are alike transformed in 

 the process of digestion ; there is no difference in the way in which 

 the vegetable and animal oily matters are emulsified, and then taken 

 up directly into the general circulation of the blood. Nor is it diffi- 

 cult to see how the starch, and sugar, and other non-nitrogenous mate- 

 rials which are peculiar to vegetable bodies are disposed of within the 

 system. The way in which starch is disposed of in the stomach and 

 bowels is not very well made out, and all that can be affirmed with 

 certainty is that a great part of it finds its way into the liver through 

 the portal system of vessels, and is detained there for a time in the 

 form of amyloid substance or glycogen a detention which is not al- 

 together unaccountable, for, as Dr. Pavy points out, this substance 

 " possesses diametrically opposite physical properties to sugar, being a 

 colloid, and therefore non-diffusible, instead of a crystalloid and diffu- 

 sible." There is no sufficient reason to suppose that the action of 

 digestion, be that what it may, is always to transform the starch into 

 sugar ; for sugar in quantity could not be formed in the stomach and 

 bowels without passing directly into the general circulation, and so 

 out from the blood into the urine by way of the kidneys without 

 making, that is to say, the phenomena of diabetes a natural state of 

 things instead of an unnatural. Nor is there sufficient reason for sup- 

 posing that the amyloid substance of the liver is transformed into 

 sugar, for this substance is as readily oxidizable and as fit for force- 

 fuel as sugar. Nay, it may be questioned whether sugar itself is the 

 force-fuel which the system is" in need of. There is a very rapid gen- 

 eration of lactic acid in the stomach and bowels when sugar is taken 

 as food, and it is not unintelligible that it should be so ; for, with the 

 help of a ferment of some sort, grape-sugar is readily converted into 

 lactic acid. Indeed, all that has to be done is for one atom of anhy- 

 drous grape-sugar to split up into two atoms of lactic acid. Nor is it 

 unintelligible that a certain part of the starch taken as food should 

 pass, as it would seem to do, not into amyloid substance or glycogen, 

 or into sugar, but first into dextrine, then into sugar, and then into 

 lactic acid : for, as is seen in the list which I show you, there is a close 



