GLOBULINS. 69 



(e) If introduced into the circulation, it is not eliminated 

 with the urine as is egg albumin. 



B. Globulins. 



Associated with the last during the life of the tissues we find 

 another class of albumins, namely, the globulins, which do not 

 dissolve in pure water, but are more or less soluble in a solution 

 of common salt. These may be divided as follows : 



1. Globulin (crystalline) occurs in many tissues, but is usually 

 obtained from an extract of the crystalline lens made by tritu- 

 rating it with fine sand in a weak solution of common salt, and 

 then passing a current of carbon dioxide through the solution. 

 The globulin falls, being easily precipitable from its saline solu- 

 tion by very weak acid. This form of globulin does not cause 

 coagulation on its being added to a serous fluid, and in this 

 respect differs from the next members of this division. 



2. Paraglobulin (fibrinoplastin) can be obtained by passing 

 through diluted serum a brisk stream of carbon dioxide. It is 

 precipitated, adding solid salt to saturation. When a fluid con- 

 taining paraglobulin is added to a serous transudation, it causes 

 coagulation of the fluid, giving rise to fibrin. 



3. Fibrinogen, a viscous precipitate got from serous fluids or 

 blood in the same way as the last, but with greater dilution and 

 more prolonged use of carbon dioxide. It is similar in its 

 characters to the last, but coagulates at a lower temperature 

 (55 C.) (paraglobulin coagulating at 60-70 C.). On its addi- 

 tion to defibrinated blood, or a fluid containing paraglobulin, it 

 forms a coagulum. 



4. Myosin, obtained from dead muscle, being the soft, jelly- 

 like clot formed during rigor mortis from the dying muscle 

 plasma. It is not so soluble as globulin, for it requires a stronger 

 solution of salt to dissolve it, and is precipitated from its saline 

 solution by solid salt or by dilution. It is coagulated at 60 C. 



5. Vitellin,^. white granular proteid obtained from the yelk of 



It is very soluble in 10 per cent, saline solution, from 

 which it can be precipitated by extreme dilution, but not by 

 Luration with salt. It coagulates between 70 and 80 C. 



