Protein — Mod ifiecl A lb u minoids 65 



lated bodies, which are typified by the white of an egg 

 after contact with boiling water, are materially unlike 

 the original compounds, though the nature of the modi- 

 fication is not understood. We know them simply as 

 coagulated albumins and globulins. 



(3) Action of acids and alkalies. When albumins 

 and globulins are treated with dilute mineral acid, such 

 as hydrochloric, they dissolve, through their conversion, 

 into acid albuminates. The action of dilute alkalies is 

 similar, only that alkali- albuminates are formed. An- 

 other effect of dilute acids upon proteids is to cause 

 them to take up water, or suffer hydrolysis. These 

 hydrolyzed bodies are called proteoses as a general 

 name. This term signifies that they are derived from 

 proteids. More fully specialized names are albumose, 

 from albumin; globulose, from globulin; caseose, from 

 casein, and so on. The important property w^hich the 

 proteoses takes on is their greater solubility as com- 

 pared with the original compounds. This change has 

 an intimate relation to digestive processes, or to the 

 transference of the insoluble albuminoids of the food 

 into the blood circulation, because in the stomach the 

 hydrochloric acid of the gastric juice plaj's somewhat 

 the same part as in dilute artificial solutions in render- 

 ing the proteids soluble. 



(4) Ferments of digestion. When we come to a 

 discussion of the processes of digestion we shall learn 

 that nearly every digestive fluid contains one or more 

 ferments, whose ofSce appears to be to cause certain 

 necessary modifications of the food proteids, The gen* 

 §VSi\ effect of these ferm§Bt§ i§ tQ JB^UCg tbe§§ proteins 



