GLOBULINS AND ALBUMIN ATES. 31 



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 tritura- 

 ting 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 solution 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 ( fibrinoplastiri) can be obtained by passing 

 through diluted serum a brisk stream of carbon dioxide. When 

 a fluid containing 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 charac- 

 ters to the last, but coagulates at a lower temperature (55 C.) 

 (paraglobulin coagulating at 60-70 C.). On its addition 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, a white granular proteid obtained from the yolk of 

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

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

 with salt. It coagulates between 70 and 80 C. 



C. Derived Albumins (Albuminates)- 



1. Acid Albumin (Syntonin) can be made from any of the pre- 

 ceding by the slow action of a weak acid ; or by the addition of 



