the Croonian Lecture. 
1 93 
a hydrocele ; and from the circumstance of the testicle being 
extirpated a month afterwards, it was ascertained that the 
coagulum had remained there four weeks before the extirpa- 
tion. The parts, immediately after the operation, were injected 
by Mr. Hunter, and the coagulum was found to be vascular. 
This is the most satisfactory proof of coagulated blood hav- 
ing vessels Mr. Hunter had met with. He has given several 
engravings of the coagulum, in his work on the Blood ; 
but, from Mr. Bell not having Mr. Bauer’s knowledge of 
drawing such objects in a magnified state, little informa- 
tion is to be received from an examination of the engrav- 
ings. It occurred to me, that by a re-examination of this 
preparation, and putting a thin section of the coagulum, con- 
tinuing the section into the substance of the testicle on which 
it lav, into the hands of Mr. Bauer, he might be able to 
make a magnified drawing of the parts, which would enable 
me to show, by comparing this drawing with the others, 
what changes are produced in the appearance of the channels, 
after they have for so long a time received the circulating 
blood; and whether the arteries by which they are sup- 
plied, had enlarged sufficiently to convert them into subor- 
dinate branches. The passages or channels originally formed 
by the extrication of the carbonic acid gas, were now found 
to have acquired a distinct coat, that admitted of being se- 
parated from the surrounding parts, showing them to be 
formed into regular tubes, but they still remained larger 
than the branches of the arteries by which they were supplied 
with blood, as will be seen by inspecting Plate XIV. 
As the globules of pus are similar to those of the blood, I 
made experiments upon the fluid in which they are suspended^. 
MDCCCXVIII. C C 
