436 OF FOOD, AND THE DIGESTIVE PROCESS. 



these again are divided transversely; gradually the transverse stride become in- 

 distinct and then disappear ; and finally the sarcolemma seems to be dissolved, 

 and no trace of the tissue can be found in the chyme, except a few fragments 

 of fibres. These changes ensue most rapidly in the flesh of fish and hares, less 

 rapidly in that of poultry and other animals. The fragments of muscular tissue 

 which remain after the continued action of the digestive fluid, do not appear to 

 undergo any alteration in their passage through the rest of the intestinal canal ; 

 for similar fragments may be found in feces, even twenty-four hours after the 

 introduction of the meat into the stomach. The cells of cartilage and fibro- 

 cartilage, except those of fish, pass unchanged through the stomach and intes- 

 tines, and may be found in the feces. The interstitial tissues of these structures 

 are converted into pulpy textureless substances in the artificial digestive fluid, 

 and are not discoverable in the feces. Elastic fibres are unchanged in the 

 digestive fluid. 1 Fatty matters are also unchanged; fat-cells are sometimes 

 found quite unaltered in the feces ; and crystals of cholesterin may usually be 

 obtained from feces, especially after the use of pork-fat. As regards vegetable 

 substances, Dr. Rawitz states that he frequently found large quantities of cell- 

 membranes unchanged in the feces; also starch-cells, deprived of only part of 

 their contents. The green coloring principle, chlorophyll, was usually un- 

 changed. The walls of the sap-vessels and spiral vessels were quite unaltered 

 by the digestive fluid, and were usually found in large quantities in the feces; 

 their contents, probably, were removed." 3 Besides the undigested residue of 

 the food, the microscope enables us to recognize the brown coloring matter of 

 the bile, epithelium-cells and mucus-corpuscles, and various saline particles, 

 especially those of the ammoniaco-magnesian phosphate, 5 whose crystals are 

 well defined ; most of which are derived from the secretions. The quantity of 

 fecal discharge which is daily passed by an adult, seems to average from 4 to 

 6 oz.; but this contains 75 per cent, of water; so that the dry solid matter thus 

 evacuated is not above 1 oz. or 1? oz. The following is the result of the proxi- 

 mate analysis of the feces of an individual in good health, who had taken the 

 ordinary diet of this country; as given by Dr. Percy. 4 



Substances soluble in ether (brownish-yellow fat) . . . . 11.95 



" " alcohol of .830 10.74 



" " water (brown resinoid matter) . . . . 11.61 



Organic matter insoluble in the above menstrua . . .,..-, 49.33 



Salts soluble in water 4.76 



Salts insoluble in water . . . 11.61 



Ultimate analysis of the same feces gave the following as the proportion of the 

 components of the Organic constituents: Carbon 46.20, Hydrogen 6.72, Nitrogen 



1 It has been pointed out to the Author by his friend, Mr. Quekett, that elastic fibres 

 are occasionally to be met with in the Human feces, which present an appearance (proba- 

 bly resulting from incipient decomposition) closely resembling that which is normal in the 

 ligamentum nuchse of the Giraffe ($ 221, note}. So distinct, indeed, does the transverse 

 division then become, that these fibres, when peculiarly abundant (as they are in the feces 

 of persons who have for some time been living upon mutton chops, and have not put aside 

 the segment of the aorta which each chop includes), have actually been mistaken for a 

 Confervoid growth in the feces. 



2 The above passage is quoted from Messrs. Kirkes andPaget's "Hand-book of Physio- 

 logy*" in which it is derived from the Memoir by Dr. Rawitz, "Ueber die Einfachen 

 Nahrungsmittel," Breslau, 1846. 



3 The presence of this salt in the feces was maintained by Schonlein to be pathogno- 

 monic of typhus ; but more recent and correct observations have shown that this view is 

 fallacious. Crystals of this salt sometimes occur in perfectly normal feces; and in those 

 cases in which the secreted fluids and the contents of the intestine readily undergo de- 

 composition, as in typhus, cholera, and certain forms of dysentery, they are found in 

 large numbers, and of considerable size. 



Simon's "Animal Chemistry" (translated by Dr. Day), p. 578, Am. Ed. 



