IX 



THE GLOBULINS 363 



dialysis, and finally the globulin is precipitated by means of dilute acetic 

 acid. The yield is, however, bad if dialysis or acidification is employed, 

 and therefore, if the presence of salt does not matter, it is better to 

 prepare globulin by repeated salting-out. As the globulin in its 

 precipitated state becomes very rapidly insoluble (see p. 298 for an 

 explanation), it is necessary to be as quick as possible in all one's 

 manipulations, according to Cohnheim; but Starke 1 is of the opinion 

 that globulin which has become insoluble in neutral salt solutions, 

 may be rendered soluble again by the addition of a trace of alkali. 



The presence of globulins in a solution may be assumed whenever 

 a coagulable, phosphor-free albumin is precipitated by diluting or 

 acidifying an albuminous solution, if in addition the precipitate gives 

 the above indicated precipitation-limits for ammonium sulphate. 



Fibrinogen, myosin, and some related substances resemble the 

 globulins as far as their acid properties and solubilities are concerned, 

 but they must be considered as belonging to a special group ; and the 

 vegetable albumins, which in part are true globulins, forms also a group 

 lay themselves. 



The rotatory power of 1 per cent globulins in 10 per cent NaCl 

 has been investigated by Alexander. 2 (See also pp. 364, 367, and 373.) 



serum-globulin -48 hemp-seed-globulin -41 '5 



egg-globulin - 40 brazil-nut-globulin - 40*5 



fibrinogen - 45 to - 50 flax-seed-globulin - 38*5 



1. Serum-Globulin 



After Panum 3 had shown that an albumin occurred in serum, 

 which could be precipitated by diluting or by acidifying the serum, 

 and after Weyl 4 had proved that this substance was a definite body, 

 to which he gave the name of serum-globulin, it was thoroughly 

 investigated by Hammarsten/' The older views of Alexander Schmidt, 15 

 who believed that serum-globulin played a part in blood-coagulation 

 and who gave to it the name of " paraglobulin," are no longer 

 tenable. 



1 J. Starke, Zeitschr. f. BioL 40. 419, 494. 



2 A. C. Alexander, Journ. of Experimental Medicine, 1. 186 (1896). 



3 P. Panum, Virchow's Arch. 4. 419 (1851). 



4 Th. Weyl, Pftiiger's Arch. f. d. ges. Physiol. 12. 635 (1876); and in Zeitschr. f. 

 physiol. Chem. 1. 72 (1877). 



5 0. Hammarsten, P/luger's Arch.f. d. ges. Physiol. 17. 413 ; 18. 38 (1878) ; and 

 in Zeitschr. f. physiol. Chem. 8. 467 (1884) ; and in Ergebnisse der Physiologie von 

 Asher-Spiro, 1. I. 330 (1902). 



6 Alexander Schmidt, Zur Blutlehre, Leipzig, 1892 (Review). 



