THE PROCESS AND THE PRODUCTS OF GASTRIC DIGESTION. 297 



THE PROCESS AND THE PRODUCTS OF GASTRIC DIGESTION. 



The mixture of finely divided food and gastric juice is designated 

 chyme. Upon this the gastric juice exerts its action. 



ACTION UPON PROTEIDS. 



The pepsin and the free hydrochloric acid are capable of transforming 

 the proteids, at the temperature of the body, into a readily soluble 

 modification that has been designated peptone. In this process the 

 proteids are changed first into bodies possessing the character of synto- 

 nins, and in this condition the solid proteids are swollen. Syntonin is 

 an acid-albuminate. By neutralization, with cautious addition of an 

 alkali, the albumin is precipitated. Then, by combination with water 

 and division into numerous small molecules, a product results, which 

 is, to a certain extent, an intermediary body between albumin and 

 peptone the albumose of W. Kuhne and Chittenden (propeptone of 

 Schmidt-Mulheim). This is soluble in water, readily soluble in dilute 

 acids, alkalies and salts. These solutions are not precipitated by boiling, 

 but by acetic acid and potassium ferrocyanid, as well as by acetic acid 

 and saturation with sodium chlorid or magnesium sulphate. Albumose 

 is precipitated by nitric acid, but it is redissolved, with the production 

 of an intense yellow color when heated, and it is again precipitated on 

 cooling. Some albumoses possess diffusibility. 



With the continued action of the gastric juice, the albumose passes 

 over into soluble and readily diffusible peptone. The unchanged pro- 

 teids behave toward the peptones as anhydrids with a large albumin- 

 molecule. The production of peptone and its solution result, therefore, 

 from decomposition with the taking up of water, brought about by the 

 hydrolytic ferment, pepsin. This action takes place best at the tem- 

 perature of the body. 



According to W. Kuhne, the proteid molecule contains two different substances, 

 namely hemi-albumin and anti-albumin. By the action on these of hydrochloric 

 acid syntonin is produced. This is next broken up into the two primary albu- 

 moses: protalbumose, soluble in water, and hetero-albumose, soluble in salt- 

 solutions. Both are then transformed into deutero-albumoses, which, in contra- 

 distinction to the primary albumoses, are not precipitated in neutral solution by 

 saturation with sodium chlorid. Deutero-albumose in contradistinction to pro- 

 talbumose is not precipitated by copper sulphate. ^ The deutero-albumoses are 

 then decomposed into peptones : hemipeptone and antipeptone. 



The pepsin enters into intimate relations with the proteid molecule. 

 The greater the amount of pepsin present, the more rapidly, to a certain 

 degree, does digestion take place. The pepsin itself undergoes almost no 

 change, and if care is taken to keep the amount of hydrochloric acid 

 always the same, it is able to digest new amounts of albumin (one 

 part 'to about 500,000 parts). Nevertheless some pepsin is consumed 

 in the process of digestion. 



The proteids are introduced into the stomach either in a liquid or 

 in a solid form. Of the liquid proteids only casein is at once coagulated 

 in solid form and precipitated and then redissolved. The other liquid 

 proteids remain liquid, are converted into the condition of syntonms, 

 and then immediately into albumoses and finally into peptones, that is, 

 actually digested. 



Uncoagulated and coagulated proteids, globulins, fibrin, som 



