CHEMICAL BASIS OF THE ANIMAL BODY. 33 



into members of the globulin class 1 . Most observers agree that the 

 globulin thus chiefly formed coagulates at 55 56. Green obtained 

 in addition one coagulating at 59 60, the two differing further in 

 their solubilities in 1 and 10 p.c. solutions of NaCl. These changes 

 are brought about by the salts in the entire absence of any putrefactive 

 phenomena, and the resulting globulins cannot be made to yield fibrin 

 again by any treatment with fibrin-ferment. 



When fresh unboiled fibrin is simply washed till it is white and 

 digested with pure active trypsin, it is largely converted into coagulable 

 proteids during the initial stages of the ferment action 2 . These 

 proteids are characteristically globulins and one is closely related to 

 paraglobulin, as judged of by its coagulating in saline solutions at 75 

 and possessing a specific rotatory power (in 10 p.c. NaCl) of (a)^ 

 = 48 '1 3 . The second globulin product of the ferment action coagu- 

 lates at 55 56, and in this respect more closely resembles fibrinogen 4 . 

 Whether the whole of the globulin thus obtained is a product of the 

 conversion of the fibrin, or whether a portion of it is due to globulin 

 existing as such in the raw fibrin, is not yet stated. Similar globulins 

 are produced by the action of pepsin in its earlier stages on raw 

 fibrin. If the fibrin is boiled or treated for some time with alcohol 

 before digestion with either of the above enzymes, mere traces, if any, 

 of these globulins are obtained. 



The purest fibrin always leaves a small but fairly constant ash- 

 residue on incineration. Of the inorganic constituents of which this 

 residue is composed it is probable that sulphur is the only element 

 which enters essentially into the composition of the fibrin. 



When boiled in water or treated for some time with alcohol it loses 

 its elasticity, becomes much more opaque, is much less soluble in the 

 various reagents which dissolve the original fibrin with comparative 

 ease, is attacked with much greater difficulty by pepsin and trypsin, 

 and is in fact indistinguishable from all other coagulated proteids. 



A peculiar property of this body remains yet to be mentioned, viz. 

 its power of decomposing hydrogen dioxide. Pieces of fibrin placed in 

 this fluid, though themselves undergoing no change, soon become 



1 Green, Jl. of Physiol. Vol. vm. (1887), p. 373. Limbourg, Zt. f. physiol. 

 Chem. Bd. xm. (1889), S. 450. The latter contains a complete list of references 

 to the literature of the subject excepting Plosz, Pfliiger's Arch. Bd. vn. (1873), 

 S. 382. 



2 Brucke, Wien. Sitzber. Bd. xxxvn. (1859), S. 131. Kiihne, Vircliow's Arch. 

 Bd. xxxix. (1867), S. 130. Lehrbuch, S. 118. Kistiakowsky, Pfliiger's Arch. Bd. 

 ix. (1874), S. 446. 



3 Otto, Zt. f. physiol. Chem. Bd. vm. (1883), S. 130. 



4 Hasebroek, Zt. f. physiol. Chem. Bd. xi. (1887), S. 348. Herrmann, Ibid. S. 

 508. But see Neumeister, Zt. f. Biol. Bd. xxm. (1887), S. 398. Salkowski, Ibid. 

 Bd. xxv. (1889), S. 97. 



