COMMENTARY. See, in particular, Hippocrates (Prognost.); and Galen (de Crisibus, xi.) Galen remarks that the stomach may do its office properly, but that, owing to the heat of the neighbouring parts, the moisture may be dissipated, and the contents of the bowels rendered too dry; or that, owing to an imperfect distribution of the chyle, they may be too liquid. When the alvine discharges are soft and consistent, we are certain that both the digestive and distributive functions are properly performed, and likewise, that no part within the belly is in a state of inflammation. He afterwards makes many other ingenious observations on this subject, the importance of which, towards the restoration of health, is now generally admitted. He remarks, that, agreeably to the description of Hippocrates (Prognost.) the proper alvine evacuation ought to be yellowish; for, if very yellow, it indicates the presence of too much bile, or, if it do not partake of that colour at all, it indicates that the passage of the bile to the intestines is stopped. Rhases and Avicenna concur in this remark. Galen describes the frothy evacuation, which appears to be the same as the one resembling yeast, described by modern authorities. Hippocrates (Progn.) and Galen makes mention of a discharge, which consists of small, hard, and convoluted portions. Galen is of opinion that it is occasioned by constipation and heat of the bowels. According to Hippocrates, a discharge of black bile indicates that death is at hand. (Aphor.) Theophilus treats of this subject at such length that we cannot afford room for a proper outline of what is contained in his treatise. Bloody evacuations, he says, proceed either from disorder of the liver, ulceration of the intestines, or rupture of a vessel. Discharges of pus may come either from the liver, or from the stomach, or from the intestines. A viscid and fatty evacuation indicates melting of the body, and if attended with a fetid smell, putrefaction. Flatus in the bowels may either arise from flatulent humours forming in the bowels, or food dissolved into gases by the heat of the parts. (De Excrementis.)