THE PUTREFACTIVE BACTERIA 229 



Escherich, Kohler, Baginsky, Bischler, and others, on the methods of nutrition 

 of B. coli commune and its powers of decomposition, was prepared by M. IDE (I.) 

 in 1891. The facts brought to light since that date will be found in the several 

 yearly volumes of A. Koch's " Jahresbericht." 



We will now briefly refer to the subject of intestinal putrefaction. Mention 

 has been made in a previous paragraph of the fundamental difference between 

 the processes of decomposition effected in the small intestine on the one hand and 

 in the colon on the other, in man. On issuing from the stomach where, by 

 the action of the pepsin and hydrochloric acid secreted by the gastric glands, a 

 more or less extensive peptonisation of the digestive albuminoids in the food has 

 been effected the pulpy food, now known as chyme, has a strongly acid reaction 

 (equivalent to 0.1-0.3 per cent, of hydrochloric acid). Immediately on its arrival 

 in the upper division of the alimentary canal (small intestine), it becomes mixed 

 with bile and pancreatic juice, under the influence of which the fat is emulsified 

 and the insoluble carbohydrates (starch) are hydrolysed. Both secretions have 

 an alkaline reaction, which, however, is not sufficiently strong to immediately 

 neutralise the acidity of the contents of the intestine. This slightly acid nutrient 

 medium, rich in sugar, offers a favourable field for the activity of the lactic acid 

 and allied bacteria introduced along with the food ; and, moreover, the acidity 

 restricts the development of the competitive putrefactive bacteria. In propor- 

 tion, however, as the contents of the intestine are forced onward and approach 

 the colon, the acid reaction is neutralised by the alkaline mucus secreted by the 

 intestinal glands. At the same time the composition of the mass has become 

 changed, since the products of the hydrolysis of starch, which have also to some 

 extent been converted by the aforesaid bacteria, have been absorbed into the 

 blood-vessels. Therefore in the contents of the colon it is the (undigested or 

 indigestible) albuminoids and biliary constituents which are decomposed by the 

 putrefactive bacteria now coming into action, and it is here that the malodorous 

 products (indole, skatole, volatile acids, sulphuretted hydrogen, &c.), to which the 

 intestinal contents (finally issuing from the rectum as faeces) owe their repulsive 

 smell, are produced. 



The researches of MACFADYEN, NENCKI, and SIEBER (III.) revealed both the 

 actual course of the process just described, and the fact that, contrary to the 

 view expressed by Pasteur, the putrefaction occurring in the colon is not essen- 

 tial to digestion. The above-named workers performed their experiments on a 

 patient suffering from a strangulated hernia at the junction of the ileum and the 

 caecum. This portion of the intestine was removed by an operation, and the 

 subsequent surgical treatment necessitated the construction of an artificial 

 evacuatory passage (anus prceternaturalis) at the extremity of the small intestine, 

 until complete union of the severed portions was restored, an affair of six months' 

 duration. Meanwhile the contents of the intestine were discharged through this 

 artificial passage, and, though no digestive functions were performed by the colon, 

 the patient nevertheless kept in good health, and even increased in weight. This 

 will explain why Nencki regarded the development of antiseptic digestion as the 

 goal of the physiology of nutrition, i.e. digestion in which the putrefaction occur- 

 ring in the colon is either abolished, or at least reduced to a minimum, in order 

 to prevent the formation of decomposition products that are not only useless to 

 the body, but even troublesome and dangerous. As a matter of fact, GEORGE 

 NUTTALL and H. THIERFELDER (I.) recently afforded a convincing proof of 

 Nencki's theory by rearing some young porpoises, born by the aid of the Csesarean 

 operation, and nourished in a suitable sterilised chamber. On examination at 

 the close of the experiment, they were found perfectly healthy, though entirely 

 free from bacteria. Pasteur's assumption (which was also supported by Soxhlet 

 with reference to his incomplete process of milk sterilising) was thus shown 



