630 



PHYSIOLOGY. 



creased the percentage of sugar, nor did large 

 meals of albumen increase that of proteids in 

 the fluid. Thus the only food stuff that leaves 

 the intestine by the lacteals is fat. 



Digestion. While it is understood that the 

 normal digestive processes going on in the liv- 

 ing alimentary tract take place under different 

 conditions from those which exist ordinarily in 

 artificial digestion experiments, physiologists 

 have been wont to assume that, so far as the 

 purely chemical part of the process is concerned, 

 the results are essentially the same. Minor dif- 

 ferences, it is true, might be expected, as in the 

 rate of action, which would presumably be more 

 rapid in gastric digestion, where the products of 

 the action are continually removed by absorption 

 and fresh digestive juice is continually secreted, 

 than in artificial methods, where the products 

 necessarily accumulate and the digestive juice is 

 limited to the original quantity. The main ob- 

 ject of a recent study by Prof. R. H. Chittenden 

 and Q. L. Amerraan was to ascertain by experi- 

 ment how far the action of pepsin-hydrochloric 

 acid on proteids is influenced by the partial re- 

 moval of the products of digestion as they are 

 formed, and whether or no, under such conditions, 

 complete peptonization is possible. The results 

 of a series of experiments for comparison of the 

 proteolytic action of pepsin-hydrochloric acid in 

 a flask with that in a dialyzer showed that the 

 slow and incomplete peptonization, supposed to 

 be characteristic of artificial gastric digestion, is 

 not materially modified by this closer approach 

 to the natural process, and favor the view that 

 the conversion of the primary products of gastric 

 digestion into true peptone is a slow and gradual 

 process, even under the most favorable circum- 

 stances. The authors believe that complete pep- 

 tonization is not a property of gastric digestion, 

 either in the artificial or in the natural process; 

 that the action of pepsin-hydrochloric acid is 

 rather a preliminary stage in proteolytic diges- 

 tion, a preparation for the more important 

 changes peculiar to the small intestine, in which 

 the more energetic alkaline-trypsin solution 

 plays a conspicuous part. This view that gas- 

 tric digestion is a preliminary step preparatory 

 to the more profound changes characteristic of 

 pancreatic digestion is confirmed by the experi- 

 ments made as to the relative proportion of pro- 

 teoses and peptone in natural gastric digestion in 

 the human stomach, in which the two albumoses 

 were found in considerable excess of the peptone. 

 It is mentioned incidentally that the gradual 

 diffusibility of the albumoses brought out by 

 the authors' experiments, in which they were 

 found to possess a certain power of osmosis, 

 through vegetable parchment, although to a 

 lesser degree than true peptone, may serve as a 

 means for their partial utilization by absorption, 

 without necessarily involving a complete conver- 

 sion into the more diffusible peptone. Proto- 

 gelatose was also found to be fairly diffusible, 

 but with a somewhat lower endosmotic equiva- 

 lent than the corresponding albumose. 



In his experiments on the fat-splitting prop- 

 erties of pancreatic juice, B. K. Radford applied 

 to the pancreatic juice of the rabbit a method 

 based upon the spontaneous emulsion method of 

 Gad. He found that the juice was alkaline, and 

 remained so for sorne time after it was removed ; 



that if it was shaken with neutral olive oil, the 

 oil rapidly took on an acid reaction, which was 

 found to be due to fatty acid ; that all the oil 

 was split into fatty acid and glycerin by from 

 one to two hours' action of the pancreatic juice ; 

 that the time required for the juice, acting in 

 glass tubes at room temperature to develop suf- 

 ficient fatty acid (o per cent.) in neutral oil to 

 give the maximum spontaneous emulsion, varied 

 with different specimens of the juice and with 

 the amount of shaking to which the juice and 

 oil were subjected, the average in the author's 

 experiments being twenty minutes ; that the 

 action of the pancreatic juice on most of the fats 

 was rapid and complete ; that while the pancre- 

 atic juice of the rabbit and neutral olive oil 

 showed only a slight tendency to the formation 

 of an emulsion by shaking the action was pro- 

 moted by adding soda solution, but the emulsion 

 did not remain good ; that a permanent pancre- 

 atic emulsion may be formed by pipetting the 

 oil from the surface of a tube containing oil and 

 juice and shaking it with the carbonate-of-sodium 

 solution. For this method great value and wide 

 application are claimed by the author, as is seen 

 in the study of the influence of bile and other 

 agents on the fat- splitting action of pancreatic 

 juice. Bile alone does not split fats. In the 

 application of the present method, however, the 

 addition of bile to the pancreatic juice greatly 

 hastened its fat-splitting action. While hydro- 

 chloric acid retarded the action, bile and hydro- 

 chloric acid mixed hastened it ; glycocholate of 

 soda and a mixture of glycocholate of soda and 

 hydrochloric acid hastened it ; carbonate of sodi- 

 um retarded it ; the actions of these various sub- 

 stances being at different rates, which are calcu- 

 lated carefully by .the author. The experiments 

 having been planned with the idea of placing 

 pancreatic juice under conditions as nearly as 

 possible resembling those under which it acts in 

 the intestine, the author infers that its action 

 must be very rapid under the favorable con- 

 ditions found in the duodenum a fact which is 

 of great physiological importance, since it is 

 evident that at this rate all the fats would be 

 split into fatty acid and glycerin in the time 

 required for intestinal digestion, unless the 

 action of the juice was checked or retarded in 

 some manner. 



The chemical products of the growth of 

 Bacillus anthracis are described by Sidney 

 Martin as including proto-albumose and dentero- 

 albumose, with a trace of peptone, all of which 

 have the same chemical reactions as the similar 

 bodies formed in peptic digestion, an alkaloid, 

 and small quantities of leucin and tyroxin. The 

 mixture of anthrax proto- and dentero-albumose 

 is poisonous, and produces oedema, with, accord- 

 ing to the magnitude of the dose, sluggishness 

 leading to stupor, coma, and death. After death, 

 great local subcutaneous oedema is found, with 

 congestion and sometimes thrombosis of the 

 small veins. Peritoneal effusion is occasionally 

 present, and the spleen is usually enlarged, dark, 

 and congested, or simply congested without 

 being greatly enlarged. The anthrax bacillus 

 in digesting the alkali-albumen forms proto- 

 albumose, dentero-albumose, and an alkaloid. 

 The alkalinity of the albumoses may explain 

 their poisonous properties, and is due to the fact 



