THE DERIVED ALBUMINS. 49 



the agency of a specific ferment. Of the manner in which this 

 transformation is effected we know but little. According to some 

 observers, the process is essentially an oxidation-process. Others 

 maintain that the fibrin is present in the fibriuogenous molecule in 

 combination with another albuminous group, and that it results from 

 the fibrinogen through decomposition of its molecule under the 

 influence of the fibrin-ferment. However this may be, it is certain 

 that the fibrinogen is not changed into fibrin through any rearrange- 

 ment of its atoms, and that a certain amount of another but 

 soluble proteid, fibrinoglobulin, is obtained whenever fibrin itself 

 is formed. It is hence a derivative of a true albumin, but not a 

 native albumin itself. 



The Coagulated Albumins. The coagulated albumins result 

 from the albumins proper through the influence of heat, prolonged 

 exposure to strong alcohol, especially in the presence of a neutral 

 salt, and in the case of fibrin at least, which, as we have just 

 seen, is closely related to this group, through the activity of a 

 specific ferment. They differ from the true albumins in their 

 extreme resistance to all neutral solvents, and also to dilute acids 

 and alkalies. Stronger acids and alkalies cause their dissolu- 

 tion, with the simultaneous formation of acid albumins or alkaline 

 albuminates. 



The Albuminates. The albuminates, as has been pointed out, 

 result from the native albumins through a process of denaturization, 

 as Neumeister terms it, in consequence of which their original char- 

 acteristics are entirely lost. Aside from their quantitative composi- 

 tion, they differ from each other only in so far as they have resulted 

 through the action of an acid or an alkali. The alkaline albu- 

 minates thus contain less sulphur and less nitrogen than the acid 

 albumins, as a portion of the sulphur and the so-called amido- 

 nitrogen have been split off. Both the acid albumins and the albu- 

 minates are insoluble in neutral solvents, and are therefore precipi- 

 tated from their solutions on neutralization. They are soluble, on 

 the other hand, in solutions of the alkaline hydrates, in dilute solu- 

 tions of sodium carbonate, in hydrochloric acid, and with a little 

 more difficulty in strong acetic acid. From their acid solutions they 

 are precipitated by salting with ammonium sulphate or sodium 

 chloride. Through the action of an alkali acid albumin can be 

 transformed into alkaline albuminate, but it is, of course, manifest 

 that the reverse cannot occur. In the living body the denaturiza- 

 tion of all albumins is effected during the process of digestion, and 

 invariably precedes the formation of albumoses and peptones. 



The Albumoses. The albumoses result from the albumins 

 proper, and also from the albuminoids and the albuminous radicles 

 of the proteids, through the action of the so-called proteolytic fer- 

 ments, or during their hydrolytic decomposition by means of acids 

 or alkalies. In every case their formation is preceded by the 

 denaturization of the original molecule. 



