872 APPENDIX. 



a flocculent precipitate, which is finally quite granular, and may easily be separated 

 by decantation and filtration ; it should be washed on the filter with water contain- 

 ing carbonic acid. 



It has usually been stated that paraglobulin may be separated from serum by 

 saturation with sodic chloride. But Hammarsten 1 has shown that this is only in 

 part true, a considerable portion of the globulin remaining unprecipitated. The 

 separation may, however, be completely effected by saturation with magnesic sul- 

 phate. When determined by this method the amount of paraglobulin in serum is 

 very considerable, amounting in some cases, according to Hammarsten, to as much 

 as 4.565 per cent, (reckoned on 100 c.c. of serum). The quantity seems to vary in 

 different animals, the precipitation being much more complete in serum from ox- 

 blood than m that from the blood of horses. 



From its solution in dilute sodic chloride, paraglobulin may be precipitated by a 

 current of carbonic anhydride or the addition of exce.edi.ugly dilute (less than 1 pro 

 mille) acetic acid. If the acid is strong, the precipitated proteid becomes immedi- 

 ately changed into acid-albumin (Class II. , 1). In pure water, free from oxygen, 

 paraglobulin is insoluble, but on shaking with air or passing a current of oxygen, 

 solution readily takes place ; from this it may be reprecipitated by a current of 

 carbonic anhydride. Very dilute alkalies dissolve this body without change ; if, 

 however, the strength of the alkali be raised even to 1 per cent, the paraglobulin is 

 changed into alkali-albumin (Class II., 2). 



According to Kuhne and A. Schmidt the solutions of this body in water con- 

 taining oxygen or in very dilute alkalies are not coagulated on heating. The 

 sodic chloride solutions do, however, coagulate when heated to 68-70 C., 2 and 

 if the substance itself be suspended in water and heated to 70 C. it is coagulated. 

 Although insoluble in alcohol, its solutions are with difficulty precipitated by this 

 reagent. 



Paraglobulin occurs not only in blood-serum, but it is also found in white cor- 

 puscles, in the stroma of red corpuscles (to some extent at least), in connective 

 tissue, the cornea, aqueous humor, lymph, chyle, and serous fluids. 



For the occurrence of globulin in urine see Edlefsen 3 and Senator. 4 



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 5 has shown that fibrinogen in a 1-5 per cent, 

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

 paraglobulin (fibrinoplastin) coagulates first at from 68-70 C. /Ihis, however, 

 is disputed by A. Schmidt, who holds that the substance coagulating at 52-55 is 

 not fibrinogen, but a sort of nascent fibrin. There is also a marked difference in 

 the precipitability of the bodies by sodic chloride. (See below. ) Other differences 

 between the two may be thus enumerated : In precipitating fibrinogen by a cur- 

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

 and the gas must pass for a much longer time. The precipitate 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. 



Fibrinogen 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. 33. 



Preparation. 6 Salted plasma, obtained by centrifugalizing blood whose coagula- 

 tion is prevented by the addition of a certain proportion of magnesic sulphate, is 

 mixed with an equal volume of a saturated (35.87 per cent, at 14 C.) 7 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 



i Pflviger's Archiv, Bd. xvii. (1878), S. 446 ; Bd. xviii. (1878), S. 38. 

 2 Hammarsten. op. cit. 



aCentralblatt f. med. Wiss., Jahrg. 1870, S. 367. Also Arch. f. klin. Med., Bd. vii. S. 69. 

 4 Virchow's Archiv, Bd. Ix. S. 476. 5 Upsala Liikareforenings forhandlingar. Bd. xi., 1876. 

 e See Hammarsten, Nov. Act. Reg. See. Sci.. Upsala, Ser. iii. vol. x. (1875), p. 31. Also Pfluger's 

 Archiv, Bd. xix. (1879), S. 563, and Bd. xxii. (1880), S. 431. 

 i Poggiale, Ann. Chim. Phys. (3), vol. viii. p. 469. 



