126 



THE BLOOD AND ITS CIRCULATION. 



the contact between the air and the fibrine closer and more 

 general. By this means the fibrine coagulates rapidly, and 

 hangs in shreds from the instrument employed. The globules 

 appear to have some share in this phenomenon, and seem to 

 aid in solidifying the fibrine. We know that coagulation 

 is retarded by the mixture with the blood of such substances 

 as sugar, salt, or any alkali. In this case a certain number 

 of the globules do not become enclosed in the fibrine, but 

 color the serum red, while the clot is paler, or even quite 

 white, in its upper coats (couenne) : these fibrous buffy coats 

 are also found in some pathological conditions, in diseases of 

 the lungs, for instance, and here we find the fibrous sponge 

 enclosing globules covered with a layer of pure fibrine, which 

 has a whitish tint, or is coated, thus containing the white 

 globules (which, by their lightness, have a tendency to rise 

 to the surface) (Fig. 36). This phe- 

 nomenon may have two different 

 causes, independently of an excess 

 of fibrine: either the blood globules 

 (the red) have become specifically 

 heavier, or coagulation is slower. In 

 the former case they are not at the 

 same level in the liquid as the fibrine 

 which floats and coagulates apart: in 

 the latter they have time to sink, 

 while the fibrine coagulates slowly. 

 In horses coagulated blood shows 

 always a buffy coat. 



The fibrine was formerly looked 

 upon as a most important part of the 

 system : it was considered, on the one 

 hand, to be the nutritive substance, 

 par excellence, perfected albumen; on the other, to be a 

 part of the organization, on account of the apparently fibrous 

 structure which it exhibits when coagulated. At present it 

 is admitted that this is a mistake : fibrine is rarely found in 

 the most nutritive substances, and the quantity in the blood 

 does not increase with the increased vigor of the subject; on 

 the contrary, it is found to accumulate after fasting, after a 

 fatiguing walk, in diseases where there is great emaciation, 

 in cases of want of nutrition, in chlorosis, etc. It is more 



* a, Level of the liquor sanguinis. c, Buffy coat, in the form of a cup. 

 I, Granular layer, with granular collection of white globules, r, Clot, with red 

 globules. (Cruor and red clot.) (Virchgw, " T>*KI! ri*ni< M \ 



Fig ' w?th~a b a uff la coat* 100d 



