754 
words, when the quantity of fibrin in the cir- 
culating part is much increased,—local inflam- 
mat.ons will be excited by very trifling causes 
(at other times quite inoperative), which are 
followed by the same results as the original one. 
But it frequently happens that the fibrinous 
element of the blood, though increased in 
quantity, does not possess its normal plasticity ; 
and the deposits which are the consequence of 
its effusion are far from being as organizable 
as in the preceding case, and are either im- 
perfectly organizable, or caco-plastic, or alto- 
gether unorganizable or aplastic. The tendency 
to such deposits may arise from various causes. 
Thus, when the inflammation is from the first of 
a low or asthenic character, or when the blood 
is previously in an unhealthy condition (as, for 
instance, when there is a deficiency in the 
number of red particles, the presence of the 
normal amount of which seems important to the 
complete elaboration of the fibrin), no other 
kind of deposit takes place from the first; and 
even when organizable plasma has been co- 
piously thrown out in the first instance, it is 
not unfrequently succeeded by caco-plastic, or 
ae products,—either from a change in the 
character of the inflammatory process itself,—or 
because the late products are thrown out in 
such a position as to be cut off from that influ- 
ence of living surfaces around, which is neces- 
sary to their complete organization. Between 
the organizable or euplastic, and the caco-plastic, 
and aplastic deposits, the gradations are almost 
insensible. The cells and fibres which are 
characteristic of the first diminish in number 
and are less perfectly formed; and they are 
replaced by a granular amorphous matter, which 
possesses but little cohesion, and which, being 
totally incapable of entering into any form of 
tissue, acts as a foreign body, and becomes a 
source of irritation. The limited space allotted 
to this subject prevents any more particular 
description of these products from being here 
given; but there is one which must not be 
overlooked, since its occurrence is very fre- 
quent, its effects upon the system most im- 
portant, and its character very peculiar. The 
1 alluded to is pus. This is characterized 
y the presence of a number of cells of a pe- 
culiar aspect, having a very tuberculated or 
- Mnulberry surface, which are seen floating in a 
fluid, termed liguor puris, which is of an albu- 
minous or low fibrinous character, being 
entirely destitute of organizability. Now the 
production of pus in an infamed part, or in 
other words, the act of suppuration, may be 
due to one of three causes, viz.,—the intensit 
of the inflammation ; the presence of air, whic 
mes a source of irritation ; and a previously 
vitiated state of the blood. Various attempts 
have been made to show that the pus-globule is 
a degenerated red or white corpuscle of the 
blood ; but it seems more probable, however, 
that it does not escape from the vessels asa 
complete cell, but as a cell-germ, which may 
have had its origin in a white corpuscle of the 
blood; and which, under favourable circum- 
stances, might have produced an exudation- 
corpuscle. Atany rate, it must be regarded as 
NUTRITION. 
a degenerated form of cell ; and the liquor puris 
must be considered as analogous to the plasma 
of the blood in a degenerated state.* 
In what manner the inflammatory 
determines the formation of the pus and 
the consequent degradation of the product, we 
are at present unable to state; but that the 
degree of irritation in the part has an influence 
upon it is evident from the effects of the contact 
of air upon inflamed surfaces, causing those 
elements to take the form of pus, which would 
otherwise have been thrown out as a plastic 
deposit. This circumstance would seem to 
indicate, beyond all doubt, that the exudation 
and pus-corpuscles, the plastic lymph, and the 
aplastic liquor puris have the same origin, but — 
that their character is determined by local cir- — 
cumstances. There is great reason to believe, 
that when pus is introduced into the blood, it 
me peinrs such a change in the ier 
the fluid, as speedily to impair its vital proper- — 
ties ; so jr rieag tags ea: will 
propagate themselves in the blood, the 
plasticity of the liquor sanguinis will be dimi- 
nished. In this manner the whole will 
be seriously affected, and there will be a tend- 
ency to deposits of pus in various 
especially those which, like the lungs liver, 
serve as emunctories to the system—without 
any previous inflammatory changes in these 
rts 
P'The last form of disordered nutrition which 
we shall consider is that which takes place ir 
the tuberculous diathesis, and which is marked 
by the deposition of tubercular matter, in place 
of the normal elements of tissue, both in the 
ordinary process of nutrition, and still more 
when inflammation is set up. From an exam 
nation of the blood of tuberculous subjects 
appears that the fibrinous element is not de 
cientin amount, but that itis notduly elabora’ 
so that the coagulum is loose, and the red ¢ 
puscles are found to bear an abnormally lov 
proportion to it. We can understand, the 
that such a constant deficiency in plasticity 
must affect the ordinary nutritive process; an 
that there will be a liability to the deposit o 
caco-plastic products, without inflammatio 
instead of the normal elements of tissue. § 
appears to be the history of the formation | 
tubercles in the lungs and other organs, 
it occurs asa kind of metamorphosis of tl 
ordinary nutritive process; and in this mann 
it may proceed insidiously for a long period, 
that a large _ of the tissue of the lungs sh 
be replaced by an amorphous deposit, withi 
any other ostensible sign than an increas 
* It would not seem improbable that the lig 
puris is the product of the action of the pus 
puscle, in the same manner as we have endeay 
to show that the li inis is the result o 
elaborating <ctine Ot tas onlonrieus : 
blood. This idea seems confirmed by the 
vation of Mr. Gulliver, that the mb 
which lines the cavity of an a , and 
which the fiuid appears to be secreted, is ch 
composed of cells that bear a strong resemblance, 
the one hand to the pus-corpuscles, and on | 
other to the colourless aca of the blo 
these cells are held together by fibrinous fibri 63 
A 
