148 CONTENTS OF THE INTESTINAL CANAL. 



green after the medicinal use of indigo ; they are often black after 

 taking bilberries or charcoal ; of a light colour after the use of 

 rhubarb, gamboge, and saffron. They are, however, also of a 

 bright yellow colour when the bile only flows sparingly into the 

 intestine, as in many affections of the liver. 



The presence of a large quantity of fat in the excrements after 

 the use of fatty food is easily accounted for, since the experiments 

 of Boussingault, as well as those of Bidder and Schmidt, show 

 that only a certain quantity of fat can be resorbed in the intestinal 

 canal : the same is observed after the use of cod-liver oil. Ac- 

 cording to Heinrich,* the amount of fat in the feeces is increased by 

 morbid action in wasting diseases, such as pulmonary phthisis, 

 Bright's disease, and diabetes mellitus ; the augmentation of fat 

 is, however, not of constant occurrence in any of these diseases. 



It has been asserted that sugar has been found in the excre- 

 ments in cases of diabetes mellitus ; its presence, however, is not 

 constant. 



The occurrence of blood in the faeces is very common, although 

 it often ^escapes observation. In haemorrhoids, dysenteries, and 

 other considerable haemorrhages of the large intestine, the presence 

 of the blood cannot be overlooked, and, as a general rule, no mani- 

 pulation or tests are requisite for its detection. If, however, the 

 haemorrhage is very slight, and proceeds from the stomach or 

 small intestine, the excrements appear variously coloured, so that 

 no conclusion regarding the admixture of blood can be drawn 

 from the colour and general appearance of the faeces. Every 

 one has seen the black or chocolate-coloured tar-like stools, which 

 were formerly regarded as peculiar to melaena, but which are 

 observed in all cases of haemorrhage in the upper part of the 

 intestinal canal, in round (perforating) ulcer of the stomach or 

 duodenum, in cancer, corrosions, &c. By a microscopic exami- 

 nation, fragments of blood-corpuscles may always be detected in 

 such excrements, and haematin may be recognised chemically by 

 means of alcohol containing sulphuric acid; in one instance (a 

 case of cancer) I found a large admixture of colourless blood- 

 corpuscles or mucus-corpuscles. In typhus, green fluid or semi- 

 fluid excrements are not very unfrequently discharged when no 

 calomel has been administered (and, conversely, it often happens 

 that the use of calomel in this disease is not followed by the 

 green stools which are characteristic of this medicine) ; and in this 

 case the green coloration is dependent on an admixture of blood, 

 * Haser's Arch. Ed. 6, S. 306. 



