BY DR. BURDON-SANDERSON. 181 



cloudy, and on standing, a flocculent deposit separates. This 

 deposit is fibrinogen. It must be collected on a filter and well 

 washed with saturated solution of common salt. If the sub- 

 stance so prepared is dissolved in a small quantity of distilled 

 water, and the liquid filtered, a clear solution of fibrinogen 

 and chloride of sodium is obtained. It possesses the property 

 of coagulating on the addition of serum, especially at a tem- 

 perature approaching that of the body. 



8. Filtered serum of blood treated in precisely the same way 

 yields a similar product containing paraglobulin. The filtrate 

 obtained determines coagulation in hydrocele liquid when 

 added to it. Coagulation may be also expected to occur when 

 the fibrinoplastic filtrate obtained in 8 is added to the fibrino- 

 genic filtrate obtained in 7. The result of this experiment is, 

 however, uncertain. 



9. If plasma is saturated with chloride of sodium in the 

 manner above described, a precipitate is obtained which con- 

 tains both paraglobulin and fibrinogen. If this is washed with 

 saturated solution of salt as before, dissolved in distilled water, 

 and rapidly filtered, a clear fluid passes through, which after a 

 while coagulates, and which has the characters of fibrin. 



10. If the transudation liquids above mentioned cannot be 

 obtained, a liquid may be prepared by adding to plasma a solu- 

 tion of a neutral salt, such as sulphate of magnesia or sulphate 

 of soda, so as to prevent coagulation. If the quantity of 

 neutral salt added is just sufficient for the purpose, the addi- 

 tion of a little paraglobulin at once determines the formation 

 of a clot. Blood is received directly from the circulation into 

 one-third of its volume of ice-cold saturated solution of sulphate 

 of soda or of sulphate of magnesia. The mixture is allowed to 

 stand in ice till next day, in order that the corpuscles may com- 

 pletely or in great measure settle. The clear liquid (plasma 

 and neutral salt solution) is then removed by decantation with 

 a capillary syphon, and used as follows : a A small quantity is 

 placed in an eprouvette, in the warm chamber, at 40 C. b 

 Other quantities are diluted with proportions of distilled water, 

 varying from 4 parts to 10 parts, and kept at the ordinary tem- 

 perature, a Coagulates at once. Of b the more dilute coagu- 

 late spontaneously, even at the orMinary temperature. To 

 those that do not so coagulate, paraglobulin is added, when it 

 is found that in the more concentrated quantities the addition 

 determines the formation of a clot. Kiihue recommends for 

 this experiment a solution of sulphate of magnesia containing 

 1 part of the salt to 3j of water. Plasma mixed with this 

 solution in the proportion of 3 parts to 1, and then diluted with 

 8 parts of water, coagulates on the addition of paraglobulin. 1 



1 Lehrbuch der physiol. Chemie, p. 172. 



