646 
THE CROONIAN LECTURE ON THE COAGULATION OE THE 
BLOOD, DELIVERED BEFORE THE ROYAL SOCIETY 
JUNE 11, 1863. 
By Joseph Lister, Esq., F.R.S., F.R.C.S. 
(Continued from p. 550.) 
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 different degrees of pres¬ 
sure), yet they are all but universally coagulable. 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 solu¬ 
tion, 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 observations are extremely 
interesting, if trustworthy; and 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 verifying 
his statements.* 
It remains to be ascertained what share the material de¬ 
rived 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 fur¬ 
nished 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 
* Since this lecture was delivered I have verified an important observa¬ 
tion made by Schmidt—viz., that a given amount of corpuscles causes com¬ 
plete coagulation of only a limited quantity of hydrocele fluid. From this 
he draws the inference that the action of the corpuscles cannot be of the 
nature of fermentation, the coagulative efficacy of the corpuscles being not 
continued indefinitely, but becoming exhausted in the process of coagu¬ 
lation. For Schmidt’s papers, see ‘Arch, fur Anat. Phys.,’ &c., 1861 and 
1862. 
