THE SERUM. 209 



and also the kinds of fat occurring in the different veins and 

 under different physiological relations, present great variety. The 

 fat of the serum as compared with that of the blood-corpuscles, 

 may he regarded as more readily crystallizable, and less tenacious 

 and colourless, but far inferior in respect to quantity. The dif- 

 ference between the quantity of fat contained in the intercellular 

 fluid and that of the blood-corpuscles is obvious from the above 

 review of the quantitative distribution of the different constituents 

 in the corpuscles and the intercellular fluid. We would only 

 observe, therefore, that the considerable quantity of fat which is 

 mixed with the fibrin, has very frequently been regarded as 

 peculiar to that constituent. Virchow* found from 2' 50 to 2'76 

 of fat which could be extracted with alcohol and ether in human 

 venous fibrin, Schmidt from 4'21 to 5'04% in the fibrin of the 

 jugular vein of horses, and from 7'37 to 8'72 in that of the portal 

 vein, whilst I found 2 '154 in the buffy coat of the venous blood of 

 the horse, ?.nd 2'168 in the arterial blood of the same animal. 



It is certainly of some importance in a physiological point of 

 view to decide whether the fat which can be extracted from this 

 substance is of a peculiar kind, and exists in chemical combina- 

 tion with it> or whether it is only incidentally mixed with this 

 substance, that is to say, from purely mechanical causes. It has 

 been usual to follow the views of Berzelius in this respect, and to 

 regard this fat as peculiar to the fibrin, and as distinguished from 

 other fats of the blood by the amount of nitrogen it contains; but a 

 more attentive consideration of the mode in which the fibrin is 

 exhibited, leads us to doubt the correctness of this opinion. We 

 have here only to consider the mode of preparation of the fibrin, 

 and. the admixtures which it always contains ; the fibrin in its 

 spontaneous coagulation must necessarily draw down and enclose 

 particles only suspended in the blood, and in addition to these and 

 the blood-corpuscles, occasionally very minute fat- vesicles, and 

 always colourless blood-cells. When the fibrin is obtained by 

 washing the clot, the granular contents of many coloured blood- 

 cells, which mainly consist of fat, remain in the fibrin together with 

 the cell-walls. We have already shown in an earlier part of this 

 work (see vol. i. page 352) that many colourless blood-cells are 

 mixed with the fibrin, and it must further be observed, that they 

 contain, absolutely and relatively ,[more fat than the coloured cells. 

 We do not call in question the possibility that acid salts of the 



* Zeitschr. f. rat. Med. Bd. 4, S. 2G6293. 



t Heller's Arch. Bd. 4, S. 322. 

 VOL. II. P 



