222 NUTRITIONAL PHYSIOLOGY 



fat thorough-going bacterial decomposition of the proteins 

 may be accomplished with the final release of highly poi- 

 sonous products. Attacks of acute indigestion resulting 

 from this cause are much like the so-called ptomain- 

 poisoning. But it is best to reserve the term for those 

 cases in which the harmful bacterial change had taken 

 place in the food before it was eaten. 



Texture is an exceedingly weighty factor in determining 

 the ease or difficulty of digestion for any food. It is this 

 which makes the recognized difference between new and 

 old bread and between the upper and the under crust of a 

 pie. Osier has said, with his usual picturesqueness, that 

 "pie north of Mason and Dixon's Line and hot bread south 

 of it have done more harm than alcohol." Fats are best 

 cared for when emulsified if liquid, and when of a flaky 

 or crystalline character if solid. This last quality is real- 

 ized in good bacon. 



Sugar. The reader will have noted that the starch, 

 which is usually the most abundant compound in the daily 

 income of man, is converted to a sugar before it is admitted 

 to the circulation. The question arises why it is not 

 equally well to eat sugar altogether in place of starch. This 

 is the actual habit during the period of milk feeding in in- 

 fancy. The enzymes that act upon starch are not freely 

 furnished until some months after birth. In later life, 

 however, starch comes to be the main reliance of the race. 

 Experience has shown that cane-sugar is often productive 

 of indigestion. Can we find definite reasons for the 

 superiority of starch to sugar? 



The fact has previously been mentioned that much sugar 

 causes alimentary glycosuria, while this is never produced 

 by the freest eating of starch. Here we have a clue to the 

 difference between the two classes of carbohydrates. 

 The glycosuria is not in itself a serious matter, but it 

 shows that the solubility of sugar and the slight changes 

 requisite for its digestion lead to its very rapid absorption. 

 The digestion of starch is a more gradual and protracted 

 process, and the resulting glucose is not formed so swiftly 



