180 THE BLOOD. 



to five hundred centimetres of distilled water. A current of 

 carbonic acid gas is allowed to pass through the liquid until 

 it becomes turbid ; much froth collects on the surface. On 

 discontinuing the current, it is found that a distinctly granular 

 precipitate has been formed. This is paraglobnlin. After 

 decanting off most of the liquid, the precipitate is collected 

 on a filter and washed with water saturated with carbonic 

 acid. It is insoluble in water which has been boiled, but 

 soluble in water containing air or ox3 7 gen ; it decomposes per- 

 oxide of hydrogen in the same way as fibrin. It is character- 

 istic of the solution that when mixed with a solution of a sub- 

 stance to be spoken of immediately under the name of 

 fibrinogen, fibrin is produced. This property is denoted by 

 the term Jibrinoplastic, which is applied both to the substance 

 and to the solution. 



2. After the precipitate has had time to subside, the clear 

 liquid is decanted off, diluted with twice its own bulk of ice- 

 cold water. A stream of carbonic acid gas is again passed 

 through it. At first it remains clear, but after a time a some- 

 what viscid scum begins to collect on the surface of the liquid 

 and on the sides and bottom of the glass. This precipitate is 

 fibronogen. This process involves an immense expenditure of 

 ice, and occupies a great deal of time. 



3. Fifty cubic centimetres of serum of ox-blood are mixed 

 with half a litre of distilled water. A stream of carbonic acid 

 gas is passed through it as before. A granular precipitate is 

 formed, which, like that obtained from plasma, is fibrino- 

 plastic. 



4. Fifty cubic centimetres of hydrocele fluid or pericardial 

 fluid are diluted with water and treated with carbonic acid 

 gas as before. A slimy white substance is formed in very 

 small quantity, which collects on the surface of the liquid and 

 on that of the glass. 



5. The granular precipitates in 1 and 3 may be obtained in 

 the same form by adding to the same diluted liquids acetic 

 acid, the quantity of which must be so small that the liquid 

 still retains a trace of alkalinity. The precipitate has the 

 characters described in 1. 



fi. Twenty cubic centimetres of filtered hydrocele or peri- 

 cardial fluid are placed in a beaker in the air bath at a tem- 

 perature of 40 C. The liquid does not coagulate, but on 

 adding serum a firm clot is formed. 



1. A second quantity of the same liquid which has been 

 ascertained by the preceding experiment to be fibrinogenic, 

 i. e., to have the property of coagulating on the addition of a 

 fibrinoplastic liquid, is saturated with pure chloride of sodium 

 by adding the salt gradually in fine powder. As the point of 

 .saturation approaches, the previously clear liquid becomes 



