238 BLOOD. 



and tuberculosis, but this is not constant ; in typhus and chlorosis 

 they do not appear to be sensibly altered in quantity. In pysemia, 

 these cells are certainly often very considerably increased in the 

 blood^ but this augmentation has been rather inferred from the 

 so-called metastatic abscesses, than directly observed. The blood 

 is, however, sometimes found to contain a great number of colour- 

 less corpuscles in conditions in which there cannot be any puru- 

 lent resorption, as, for instance, in the case of dogs affected with 

 cutaneous eruptions. 



We will now proceed to the consideration of those modifica- 

 tions in the chemical composition of the intercellular fluid, which 

 have been observed to occur under different physiological and 

 pathological relations, and will endeavour to arrange them accord- 

 ing to the augmentation or diminution of the individual con- 

 stituents. We will begin with the fibrin ; but as we have already 

 considered the most important points in reference to this subject 

 (see vol. i., p. 357), little more remains to be noticed regarding it. 



Opinions are not wholly agreed as to the quantitative difference 

 of the fibrin in venous and in arterial bloody although Lecanu and 

 Nasse coincide in believing that arterial is richer in fibrin than 

 venous blood ; and in this respect their opinion corresponds with 

 my own experiments on horses 5 blood, in which I found 6'814 p.m. 

 of fibrin in the arterial blood, and 5-384 p.m. in the jugular venous 

 blood; but while the quantity of fat in the blood- cells and in the 

 serum differed in both kinds of blood, it was almost perfectly 

 equal in the arterial and in the venous fibrin (namely, 2*154^ in 

 venous and 2'168-g- in arterial dry fibrin). I found rather more 

 ash (2'l72f) in the fibrin of arterial than in that of venous blood 

 (1'907-g-). The fibrin of arterial blood coagulates more rapidly 

 than that of venous blood. In both kinds of blood, when taken 

 from the horse, there is generally formed a superficial layer of 

 fibrin ; but this is much more extensive in venous blood, and also 

 more distinctly limited by the clot, than in arterial blood, which 

 may perhaps be mainly owing to the more rapid coagulation of the 

 arterial fibrin, rather than to the less rapid sinking of the cells of 

 the arterial blood, for these are specifically heavier than the venous 

 blood-corpuscles (being poorer in fat and richer in heematin), and 

 should therefore sink more rapidly. 



In reference to the difference in the quantity of the fibrin con- 

 tained in portal and in hepatic venous blood, I may simply remark 

 that, as has been already stated, I found from 4 to 6-g- of fibrin in 

 the portal blood, whilst in hepatic venous blood there were only 



