3*7 
and Expenments on Pus . 
cannot be readily, or at all completely separated again from 
one another. There is indeed, in these cases, no necessity for 
the admission of the secretion of the limpid fluid of pus of 
abscesses (Sect VII. 1) ; for it appears to me not unjust to 
consider mucus to be nothing more than the serum of blood, 
altered in its composition and proportion of water, so as to 
produce a viscid texture. The secretory organs of the mucous 
membrane, by virtue of their peculiar power, separate from 
the blood, in health, the mucus as above said, with some 
globules, and also a small proportion of the self-coagulable 
lymph ; which appears, on agitating mucus in a large propor- 
tion of cold water, in the form of leafy and fibrous masses.* 
The same secretory organs, it is easily conceivable, may in a 
diseased state, be excited to separate also self-coagulable 
matter from the blood, with more globules, in such a state as 
to become pus. Hence, such a commixture of the two sub- 
stances must correspond to the opaque, viscid, expectorated 
sputum, of which I am writing. 
If I thought farther reasoning proper, it would be manifest, 
that all the phenomena, both in health and disease, belonging 
to the various kinds of sputum, consist with the theory above 
delivered. 
* Serum of blood appears always to contain self-coagulable lymph, which is de- 
posited on standing ; and this appearance led Gaeer, Pringle, and Cullen, into 
the erroneous opinion, of this deposit being pus itself. 
r 
MDCCCX. 
