1863.] 607 



put forwara '-/ingenious pathologists to account for this difference. 

 But it now appears that a dropsical effusion, like that of hydrocele, 

 is undistinguishable from pure liquor sanguinis. 



Various dropsical effusions have been lately investigated with 

 reference to their coagulability on the addition of blood-corpuscles, by 

 Dr. Schmidt of Dorpat, who finds that .while they differ from one 

 another in the amount of water they contain (just as is the case 

 with serum filtered artificially through animal membranes under dif- 

 ferent degrees of pressure), yet they are all but universally coagu- 

 lable. Schmidt has also carried the investigation further. He has 

 found that by chemical means he can extract from the red corpuscles 

 a soluble material which, when added to these exudations, leads to 

 coagulation. In other words, he shows that the corpuscles do not 

 act as living cells, but by virtue of a chemical material which they 

 contain, which can be used in the state of solution, free from any 

 solid particles whatever. He found also that the aqueous humour 

 made a dropsical effusion coagulate, and that the same effect was 

 produced by a material extracted from the non-vascular part of the 

 cornea. Hence he regards the blood-corpuscles as only resembling 

 other forms of tissue in possessing this property. These observa- 

 tions are extremely interesting, if trustworthy; arid .that they are 

 so, I do not at all doubt ; but having only read Schmidt's papers 

 within the last day or two, I have not yet had opportunity of verify- 

 ing his statements*. 



It remains to be ascertained what share the material derived from 

 the corpuscles has in the composition of the fibrin. Schmidt inclines 

 to the opinion that the fibrin is probably composed, in about equal 

 proportions, of a substance furnished by them and one present in 

 the liquor sanguinis. If this be true, the action of an ordinary solid 

 in determining the union of the components of the fibrin may be 

 compared to the operation of spongy platinum in promoting the com- 

 bination of oxygen and hydrogen. 



* Since this lecture was delivered I have verified an important observation 

 made by Schmidt, viz. that a given amount of corpuscles causes complete coagu- 

 lation of only a limited quantity of hydrocele-fluid. From tbis he draws the 

 inference, that the action of the corpuscles cannot be of the nature of fermenta- 

 tion the coagulative efficacy of the corpuscles being not continued indefinitely, 

 but becoming exhauster! in the process of coagulation. For Schmidt's papers, 

 see Archiv fiir Anat. Phys. &c. 1861 and 1802. 



