APP.] CHEMICAL BASIS OF THE ANIMAL BODY. 711 



least), in connective tissue, the cornea, aqueous humour, lymph, chyle, 

 and serous fluids. 



For the occurrence of globulin in urine see Edlefsen l and Senator 2 . 

 3. Fibrinogen. 



The general reactions of this body are identical with those of 

 paraglobulin. The most marked difference between the two is 

 the point at which coagulation of their solutions takes place. 

 Hammarsten 3 has shewn that fibrinogen in a 1 5 p. c. solution of 

 sodic chloride coagulates at from 52 55 C., whereas, as stated above, 

 paraglobulin (fibrinoplastin) coagulates first at from 68 70 C. This 

 however is disputed by A. Schmidt who holds that the substance 

 coagulating at 52 55 C. is not fibrinogen but a sort of nascent fibrin. 

 There is also a marked difference in the precipitability of the two bodies 

 by sodic chloride. (See below.) Other differences between the two 

 may be thus enumerated : In precipitating fibrinogen by a current 

 of carbonic anhydride, the containing fluid must be much more strongly 

 diluted, and the gas must pass for a much longer time. The pre- 

 cipitate thus obtained differs from that of paraglobulin in that it 

 forms a viscous deposit, adhering more closely to the sides and bottom 

 of the containing vessel ; there is also no flocculent stage previous 

 to the viscous precipitate. 



Eibrinogen occurs in blood, chyle, serous fluids, and in various 

 transudations. The relations of fibrinogen and paraglobulin to the 

 formation of fibrin have been discussed in the text, p. 18. 



Preparation 4 . Salted plasma, obtained by centrifugalising blood 

 whose coagulation is prevented by the addition of a certain proportion 

 of magnesic sulphate, is mixed with an equal volume of a saturated 

 (35-87 p.c. at 14 C.) 5 , solution of sodic chloride; the fibrinogen is thus 

 precipitated while the paraglobulin remains in solution. The adhering 

 plasma may be removed by washing with a solution of sodic chloride 

 and the fibrinogen finally purified by being several times dissolved in 

 and reprecipitated by sodic chloride. 



There is no proof that the whole of the substance thrown down by 

 carbonic anhydride from diluted blood-serum is fibrinoplastic, indeed we 

 know that a true globulin devoid of fibrinoplastic properties may be 

 prepared from serum 6 . Weyl 7 considers that there is only one globulin 



1 Centralblatt f. d. med. Wiss. Jahrg. 1870, S. 367. Also Arch. f. klin. Med. Bd. 

 vii., S. 69. 



2 Virchow's Archiv, Bd. LX., S. 476. 



3 Upsala Ldkareforenings forhandlingar. Bd. xi. 1876. 



4 See Hammarsten, Nov. Act. Reg. Soc. Sci. Upsala, Ser. in. Vol. x. (1875),.- 

 p. 31. Also Pfliiger's Archiv, Bd. xix. (1879) S. 563, and Bd. xxn. (1880), S. 431. 



5 Poggiale, Ann. Chim. Phys (3) Vol. vm. p. 469. 



6 Kiihne and Eichwald, loc. cit. 7 Loc. cit. 



