400 HANDBOOK OF PHYSIOLOGY. 



tinal fluids, and is absorbed chiefly by the blood-vessels. During or just 

 prior to its absorption, maltose is converted into dextrose. 



(4.) Saline and saccharine matters, such as common salt, and cane 

 sugar, if not in a state of solution beforehand in the saliva or other fluids 

 which may have been swallowed with them, are at once dissolved in the 

 stomach, and if not here absorbed, are soon taken up in the small intes- 

 tine; the blood-vessels, as in the last case, being chiefly concerned in the 

 absorption. Cane sugar is in part or wholly converted into grape sugar 

 before its absorption. This is accomplished partially in the stomach, but 

 also by a ferment in the succus entericus. 



(5.) The liquids, including in this term the ordinary drinks, as water, 

 wine, ale, tea, etc., which may have escaped* absorption in the stomach, 

 are absorbed probably very soon after their entrance into the intestine; 

 the fluidity of the contents of the latter being preserved more by the 

 constant secretion of fluid by the intestinal glands, pancreas, and liver, 

 than by any given portion of fluid whether swallowed or secreted, re- 

 maining long unabsorbed. From this fact, therefore, it may be gathered 

 that there is a kind of circulation constantly proceeding from the intes- 

 tines into the blood, and from the blood into the intestines again; for 

 as all the fluid a very large amount secreted by the intestinal glands, 

 must come from the blood, the latter would be too much drained, were 

 it not that the same fluid after secretion is again reabsorbed into the 

 current of blood going into the blood charged with nutrient products 

 of digestion coming out again by secretion through the glands in a 

 comparatively unchanged condition. 



At the lower end of the small intestine, the chyme, still thin and 

 pultaceous, is of a light yellow color, and has a distinctly faacal odor. 

 This odor depends upon the formation of indol and other substances to 

 be again alluded to. In this state it passes through the ileo-cascal open- 

 ing into the large intestine. 



Summary of the Digestive Changes in the Large 

 Intestine. 



The changes which take place in the chyme in the large intestine 

 are probably only the continuation of the same changes that occur in 

 the course of the food's passage through the upper part of the intestinal 

 canal. From the absence of villi, however, we may conclude that ab- 

 sorption, especially of fatty matter, is in great part completed in the 

 small intestine; while, from the still half-liquid, pultaceous consistence 

 of the chyme when it first enters the caecum, there can be no doubt that 

 the absorption of liquid is not by any means concluded. The peculiar 

 odor, moreover, which is acquired after a short time by the contents of 

 the large bowel, would seem to indicate a further chemical change in 



