SERUM-GLOBULIN. 



[BOOK i. 



that magnesium sulphate, added to complete saturation, precipitates 

 every trace of paraglobulin present in a solution, whilst it has no 

 action on serum-albumin, Hammarsten has by its aid determined 

 how much paraglobulin the blood serum contains. His determina- 

 tions would appear to leave no doubt that paraglobulin is in many 

 cases the chief proteid of the serum, as can be seen by studying the 

 accompanying table : 



Properties Serum-globulin precipitated by any of tbe methods 



buST" 11 " 510 " Described is found to be soluble in water holding C0 2 

 in solution, in water holding oxygen in solution, in 

 very weak aqueous solutions of the alkalies, in lime water, in weak 

 solutions of neutral alkaline salts, in solution of sodium phosphate 

 and of the carbonates of the alkalies. 



When considerable quantities of serum-globulin are dissolved in 

 very weak solutions of the alkalies, perfectly neutral solutions are 

 obtained which are not coagulated by heat, but which are so when 

 very cautiously treated with acetic, hydrochloric, nitric, or sulphuric 

 acids, the precipitate being readily dissolved by an excess of the 

 reagent; such weak alkaline solutions are precipitated by the addition 

 of a large quantity of alcohol. 



Serum-globulin is in great part, though by no means completely, 

 precipitated when sodium chloride is dissolved to saturation in its 

 solution ; the precipitated serum-globulin is found to be soluble in 

 weak solutions of sodium chloride. 



It was stated by A. Schmidt that paraglobulin is completely precipitated 

 by the addition of powdered NaCl to its solutions, but Eichwald and 

 Hammarsten, and especially the latter, have shewn conclusively that 

 Schmidt was in error. On the other hand, the body to be next described, 

 viz. Fibrinogen, is completely precipitated when treated in the same manner 

 by NaCl. 



According to Hammarsten 1 , if a very small quantity of common 



1 Hammarsten, "Ueber das Paraglobulin," Zweiter Abschnitt. Pfliiger's Archiv, 

 Vol. xvni. (1878) p. 39 et seq. 



