NUTRITION. 
left at rest. A case has fallen under the writer’s 
observation, in which both limbs were affected 
with almost complete (hysteric) paraplegia ; 
but one was also frequently seized with violent 
cramps, from which the other was free; the 
difference in the muscularity of the two limbs 
was very striking, and was evinced by the 
greater circumference of the one affected with 
cramps (which was an inch and a half larger 
round than the other), as well as by its greater 
firmness of flesh. Similar facts may be ad- 
duced, in regard to atrophy of nerves, from 
interruption of their normal function. Thus 
when the cornea has been rendered so opaque 
by accident or disease, that no light can pene- 
trate to the interior of the eye, the retina and 
the optic nerve lose, after a time, their charac- 
teristic structure ; so that scarcely a trace of the 
peculiar globules of the former, or of the nerve- 
tubes of the latter, can be found in them. 
These and similar facts are readily understood, 
when connected by the general principle for- 
merly laid down,—that every proper vital 
' Operation involves an act of nutrition ; in such 
a manner that, whilst the vital properties ofany 
part are dependent upon its. due nutrition, the 
amount of its nutrition will in return depend 
_ upon the degree in which these properties are 
exercised. 
_ Partial atrophy may depend, however, upon 
causes of a purely mechanical nature; such, 
for example, as produce an interruption of the 
current of blood through the part. This may 
result from changes in the arteries supplying it, 
such as ossification, or other forms of obstruc- 
tion. Or it may be consequent upon disease 
in the part itself; as when the deposits produced 
_ by inflammation tend to contract, and thus to 
press upon the vascular structure, which fre- 
quently happens in the lungs, liver, and 
kidneys; or when the inflammation occurs in 
the vessels themselves, causing adhesion of 
their walls, and obliteration of their tubes; or 
_ when a new growth absorbs into itself all the 
_ hutritive materials which the blood supplies. 
_ _ Abnormal forms of the nutritive process.— 
Under the preceding head we have considered 
the chief variations in the degree of activity 
| that are witnessed in the ordinary or normal 
conditions of the nutritive process,—that is, 
| those conditions in which the products are 
adapted by their similarity of character to re- 
‘place those which have been removed by dis- 
| integration. But we have now to consider 
“those forms of this process, in which the pro- 
ucts are abnormal,—being different from the 
tissues they ought to replace. We shall con- 
_ fine ourselves to a brief examination of the two 
_ most important of these states ;—that which is 
‘termed inflammation, and that which gives 
Tise to tubercalar deposit. The former results 
from an eacess of the plastic element in the 
blood : the latter from a depraved condition of 
it, og its plasticity is impaired or de- 
B Nowithstinding all the attention which has 
: given to the state of the vessels in inflam- 
mation, a careful consideration of its phenomena, 
with the light which recent investigations have 
VOL. III. 
753 
thrown upon these, leads us to attach com- 
paratively little importance to this, and to seek 
for the essential character of ‘the process else- 
where. The researches of Addison, Williams, 
Barry, Gulliver, Andral, and others, all seem 
to point to the following conclusions.—1. That 
there is a peculiar afflux or determination of the 
white corpuscles of the blood towards the in- 
flamed part. 2. That the total amount of these 
corpuscles in the circulating blood undergoes 
a great increase. 3. That the quantity of fibrin 
in the blood augments in proportion to the ex- 
tent and intensity of the inflammation; and 
this even when it was previously, from the 
influence of some other morbid condition, 
below the usual standard. With its quantity, 
its plasticity or tendency to organization also 
increases in a, healthy subjéct. Now when 
these facts are compared together, and are con- 
nected with those formerly adduced, in regard 
to the probable function of the white corpuscles 
of the blood, they lead almost irresistibly to the 
conclusion, that the process of inflammation 
essentially consists in an undue stagnation of 
the white corpuscles of the blood in the vessels 
of the part, an excessive multiplication of these 
by the ordinary process of generation, and a con- 
sequent over-production of fibrin. By these 
changes, and by the results which follow them, 
inflammation may be distinguished from the 
various forms of hyperemia and congestion. 
To the results, then, we shall next direct our 
attention. 
It may be inferred, we think, from various 
phenomena, that whilst the formative power of 
the blood is increased in inflammation, that of 
the ¢issues is diminished. Certainly this is the 
case in regard to the system at large, when 
febrile irritation has been established ; for, not- 
withstanding the increased plasticity of the blood, 
we see the body wasting, instead of increasing in 
vigour. And it may be inferred, also, in regard 
to the tissues of the part affected, from the ten- 
dency to atrophy and disintegration which they 
exhibit ; and whichis greater (leading even to the 
death of whole parts) in proportion as the ifi- 
flammation is more intense, and as the tendency 
to the deposit of new products is the more 
decided. That a stagnation of blood takes 
place in the vessels of the inflamed part is 
another general fact, which throws some light 
upon the nature of the process ; for this stag- 
nation is obviously favourable to the transu- 
dation of the fluid plasma of the blood, through 
the walls of the vessels, into the surrounding 
tissue, or upon a neighbouring surface. This 
deposition of the fibrinous element, possessing a 
high degree of plasticity, and capable of spon- 
taneously passing into simple forms of tissue 
(which may be gradually replaced by higher 
forms, when penetrated by vessels from the 
surrounding parts), may be regarded as the 
first characteristic result of inflammation. That 
this deposition of the fibrin, which has accu- 
mulated to an unusual extent in the blood, 
should take place only in the inflamed part, 
cannot perhaps be very readily accounted for; 
but we see that, when the inflammatory 
diathesis is once established,—or, in other 
3c 
