PLASTIC EXUDATIONS. 133 



fibrin becomes perfectly dissolved after digestion for some time at 

 a temperature of 30 in a solution of nitre, being converted into a 

 coagulable fluid. In water containing hydrochloric acid, the exu- 

 dation swells up in a gelatinous form, but does not dissolve, in 

 which respect, as in all other reactions, it perfectly coincides with 

 the blood-fibrin. Precisely the similar remark applies to the 

 albumen ; and the mineral constituents, in as far as we can 

 determine them from the small quantities of these exudations 

 generally at our command, differ in no essential respect from those 

 occurring in the liquor sanguinis. 



No detailed quantitative analysis can be made with very recent 

 exudations owing to the small quantities in which they are obtained. 

 I have, however, constantly found more water in them than in the 

 liquor sanguinis, which is the more striking, seeing that in collect- 

 ing these fluids the evaporation of the water cannot be so readily 

 prevented as when the blood is drawn from the opened vein. In 

 five experiments on rabbits and in three on geese, I found from 1'94 

 to 4'28-g more water in the secretion from the wound than in the 

 plasma of the mixed blood, that is to say, of the mixture of 

 arterial and venous blood, which was obtained from the carotid 

 and jugular vein. I could not determine with any degree of 

 certainty whether the amount of fibrin in the exudation was 

 greater or less than that in the liquor sanguinis ; but the quantity 

 of albumen was decidedly somewhat smaller than in the blood- 

 serum, the difference being greater than could be accounted for by 

 the relative increase of water in the exudation. In geese there 

 was always rather more fat in the exudation than in the corres- 

 ponding liquor sanguinis ; but here it was difficult to determine 

 whether the fat from the subcutaneous cellular tissue was not in 

 part mixed with the secretion from the wound. No difference 

 could be detected in the quantity of salts contained in both fluids. 

 Strict determinations in the case of the phosphates and metallic 

 chlorides on the one hand, or of the soda and potash salts on the 

 other, were impracticable ; but I endeavoured in six cases to 

 determine the average proportions of these substances in the 

 secretion from the wound and in the corresponding blood-serum, 

 and I think that I am scarcely in error in stating that the 

 secretion from the wound contains relatively more of the phos- 

 phates and potash salts, and that the serum contains an excess of 

 soda salts and chlorides. 



The very recent exudations obtained in rare cases from the 

 serous sacs of human subjects present very different relations, not 



