746 
rous as the red particles: this, Mr. Gulliver 
has frequently noticed in fatal deer of about 
an inch and a half long. In a still smaller foetus 
the blood was pale from the preponderance of 
the white corpuscles. It is, therefore, a fact of 
much interest that, even in the mammiferous 
embryo, at the period when growth is most 
rapid, the circulating fluid has a strong analogy 
to that of the Invertebrata. It then, too, bears 
in other respects the most striking analogy to 
chyle; since it consists of the fluid elaborated 
from the organizable matter supplied by the 
parent, and direct/y introduced into the current 
of the circulation. The function of the placental 
vessels may be regarded as double ; for the 
are at the same time the channel, through which 
the alimentary materials supplied by the pa- 
rent are introduced into the circulating system 
of the fetus, aud the medium of aerating the 
fluid which has traversed the fetal system. 
Hence the placenta may be regarded as at 
once the digestive and the respiratory appa- 
ratus of the fetus, and the fluid circulating 
through the cord as at once chyle and blood. 
It is not until the pulmonary and lacteal vessels 
of the embryo have commenced their indepen- 
dent operation, that the distinction between the 
blood and the chyle of the fatus becomes evi- 
dent; and we should expect, therefore, to find 
that the circulating fluid, up to the time of 
birth, contains a large proportion of white cor- 
puscles, which is actually the case. There is a 
gradual decrease, however, in their proportional 
number, from the earlier to the later stages of 
embryonic life, in accordance with the dimi- 
nishing energy of the formative processes. It 
has been also observed by Wagner* that the 
number of colourless corpuscles is always re- 
markably great in the blood of well-fed frogs 
just caught in the summer season ; and that it 
is very small in those, which had been kept long 
without food, and in those examined during the 
winter. 
The most remarkable evidence, however, of 
the connection between the generation of white 
corpuscles in the blood, and the production of 
fibrin, is derived from the phenomena of in- 
flammation. A decided increase in the normal 
proportion of fibrin in the blood (from 24 to 
3$ parts in 1000) may probably be looked 
upon as the essential indication of the existence 
of the inflammatory condition. For it appears 
from the observations of Andral and Gavarret 
(which have been confirmed by many other 
pathologists) that such an increase uniformly 
manifests itself, when a local inflammation com- 
mences,—even when the proportion of fibrin 
~ has previously been abnormally low, as in 
febrile diseases ; that it bears a constant rela- 
tion with the extent and intensity of the diseased 
action ; and that it diminishes with the abate- 
ment of the morbid condition of the part affected. 
In some instances, the proportion of fibrin was 
seen to rise as high as 9 or even 10 parts in 
1000; but an increase to the amount of 6, 7, 
8 parts, was more common. That this pro- 
duction of fibrin is due to a local change can 
* Op. cit. p. 245. 
NUTRITION. 
scarcely be doubted; since it is frequently — 
chaired to commence before 7 ee i 
tutional symptoms manifest themselves; and it — 
may be regarded, in fact, as one cause of these — 
symptoms. Now the recent mi ic ob- 
servations of Mr. Addison* and Dr. Willi a 
which were made independently of each other, — 
have established the im t fact, that a 
great accumulation of white corpuscles takes 
place in the vessels of an inflamed part; and 
this seems to be caused at first by a deter- 
mination of those already existing in the cireu- 
lating fluid, towards the affected spot; but 
partly by an actual increase or generation ¢ 
these bodies, which appear to have the powe 
of very rapidly multiplying themselves. The 
accumulation of white corpuscles may be easily 
seen, by applying irritants to the web ofa fro s 
foot. Mr. Addison has noticed it, in the 
human subject, in blood drawn b Fee Dr 
of a needle, from an intlamed pimple, the base 
of a boil, the skin in scarlatina, Ke. Am 
the writer, without any knowledge of thesi 
observations, had remarked a very obviou 
difference between the proportions of whiti 
corpuscles, in blood drawn from a wound — 
the skin of a frog immediately upon the ineisi 
being made, and in that drawn a few minu 
after; and had been led, like the observ 
just quoted, to refer this difference to a dete 
mination of white corpuscles to a part irritates 
The absolute increase, sometimes to a very cor 
siderable amount, in the quantity of whi 
corpuscles in the blood of an inflamed subj 
has been verified 5 Gulliver and sever 
other observers. ese facts, therefore, affo 
strong ground for the belief, that the producti 
of fibrin in the blood is closely connected 
the development of the white corpuscles; a 
when we consider them in connection with | 
facts previously urged, there scarcely appear 
be a reasonable doubt, that the elaboratior 
fibrin is a consequence of this form of cell- 
and is, in fact, its express object. . 
A recent observation of Mr. Addison’, t 
over, would seem to indicate, that no ineonsi 
able proportion of the fibrin of the cireuls 
blood is contained within the white corpus 
“ Provide six or eight slips of glass, su cha 
usually employed for mounting micros¢o) 
objects ; and as many smaller pieces. 
drawn blood from a person with 
fever, or any other inflammatory dise 
a drop of the colourless liquor sanguinis, b 
it fibrillates, on each of the large slips of | 
cover one immediately with one of the 
slips, and the others one after anuther af 
vals of thirty or forty seconds: th 
examining them by the microscope, 
will exhibit colourless blood corpt 
various conditions, and numerous 
cules distributed through a more or less ¢ 
fibrous network ; and the last will be 
coherent, and very elastic membrane, 
cannot be broken to pieces nor resolv 
en Gazette, Dec, 1840; Jan. and 
+ Medical Gazette, July, 1841; and Pr 
of Medicine, pp. 209, 210. ae 
