46 DENIS' PLASMINE. SCHMIDT'S VIEWS. [BOOK i. 



these most interesting results of Professor Buchanan have not formed 

 part of the common stock of scientific knowledge, and are generally 

 known only as re-discovered and greatly added to by Professor Alex- 

 ander Schmidt of Dorpat. 



Denis' Although Buchanan believed in the existence of 



fibrin in solution in the liquor sanguinis he had no idea 



tion to Fibrin ^ separating the dissolved substance. Denis in 1859 



announced 1 the separation from the plasma of aproteid 



body to which he gave the name of Plasmine and which yields 



fibrin as a product of decomposition. 



Denis commences by mixing uncoagulated blood with one-seventh 

 its volume of a saturated solution of sodium sulphate. After the 

 corpuscles have subsided, the supernatant mixture of liquor sanguinis 

 and solution of sodium sulphate is decanted and sodium chloride 

 is added little by little as long as it is dissolved. The solution be- 

 comes turbid and soon acquires a creamy consistence, from the separa- 

 tion of a bulky flocculent precipitate. The fluid is thrown upon a. 

 filter and washed with a saturated solution of sodium chloride. 

 The matter which remains undissolved is the plasmine of Denis. 

 Of this plasmine Denis obtained 14*59 grammes from 1000 grammes 

 of human blood. 



If plasmine, thus precipitated through the agency of sodium 

 chloride, be placed in water, the solution, in the course of a few 

 minutes, undergoes spontaneous coagulation; the coagulum consists 

 of fibrin similar to that obtained directly from blood, and the amount 

 yielded by the plasmine also corresponds with that which would 

 have been obtained directly from blood. In addition, however, to 

 the insoluble fibrin which separates, there is found to be present in 

 the solution a proteid substance to which Denis gives the name of 

 'fibrine soluble' to distinguish it from the first 'fibrine concrete' or 

 'fibrine ordinaire/ 



Denis therefore believed that the precursor of fibrin in the blood 

 is a complex body, plasmine, which at the moment of coagulation 

 splits up into two proteids, of which the one separates in the form of 

 the insoluble fibrin and the other dissolves in the serum. These 

 views of Denis will be again referred to when speaking of the more 

 recent investigations of Hammarsten. 



The disco- The fundamental fact discovered by A. Schmidt was 



veries and the very same which it has been shewn was clearly 

 hypotheses of described long before him by Dr Andrew Buchanan, viz. 

 A. Schmidt. that there occur animal fluids from which fibrin does 

 not separate spontaneously but only after the addition of blood or of 

 blood-serum, or certain of their constituents 2 . 



1 Denis, Nemoire sur le sang, 1859, p. 32. 



2 A. Schmidt, "Ueber den Faserstoff und die Ursachen seiner Gerimmng." Archiv 

 f, Anat. u. Physiolog., 1861, p. 545. 



