BLOOD. 
126 
hath not revealed it unto thee,'but my Father which is in 
heaven. Malt/i. xv i. 17.—Temper of mind; hate of the 
pafiiuns : 
Will you, great fir, that glory blot, 
In cold blood, which you gain’d in hot ? Hudibras. 
Hot fparlc; man of fire.—The news but drives young 
bloods into Inch a fury, as the ambafladors were not, with, 
out peril, to be outraged. Bacon. —The juice of anything. 
He waffled his garments in wine, and his clothes in the 
blood of grapes. Gcvcfis, xlix. 11. 
Though there is no living creature known in the whole 
world, whofe life does not immediately depend upon the 
circulation of fome kind of fluid through its veflels, yet, 
unlefs Inch fluid is of a red colour, it does not obtain the 
name of blood ; and therefore fuch creatures as have aco- 
Idurlefs or milky liquor circulating through their veflels, 
are called exfanguious animals. The blood has a very dif¬ 
ferent degree of thicknefsor vifeidity in different animals, 
and even in the fame animal at different times. Though 
it is in all cafes endowed with a confiderable degree of te¬ 
nacity, yet in ftrong animals that tenacity is remarkably 
greater than in weak ones ; and hence the blood of bulls 
was made ufe of by the ancients as a poifon, its extreme 
vifeidity rendering it totally indigeftible by the powers of 
the human flomach. When blood is taken from the bo¬ 
dy, it immediately lofes its volatile part, which flies off 
in the form of a vapour, and is of the nature of fal am¬ 
moniac. When this vapour is diflipated, the remaining 
blood quickly congeals into a trembling mafs. The prin¬ 
cipal part of this coagulated mafs is the crajfamentum , 
which hath the red colour to itfelf, and gives it to the 
other parts ; when this craffamentum is freed from its wa¬ 
tery part, it is wholly inflammable. The next part of the 
blood is th e ferum ; from this is formed what is called the 
pleuritic crujl on the furface of the blood, after taking it 
from a vein by the ufual method of bleeding ; of this po- 
lypufes and artificial membranes are alfo formed. In this 
l’er'um, befides the albumen , which hardens like the white 
of an egg, there is much water, and a fmall quantity of 
ropy mucus. Befides thefe parts, a portion of fea-falt is 
found in the blood, and is manifeff to the take, and often¬ 
times to the microfcope. By a chemical analyfis, a fine 
chalky earth is alfo found to exift in the mod fluid parts of 
the blood ; a portion of fixed air to the amount of half a 
fcruple in every ounce ; and alfo a fmall quantity of iron, 
which the loadfione will attraft. To thefe may be added 
the elementary fire. 
The natural elements of the blood formed by the ani¬ 
mal economy are, the albumen, and the globules. The al¬ 
bumen is the immediate matter of growth and nutrition. 
The globules never pafs the emunftories, except by ex- 
cefs or difeafe; as for the faline, morbid, bilious, and 
other, particles that are found in the circulating blood, 
they are rather hetorogeneous than elementary parts of it. 
In an healthy date the blood is mild and gelatinous, but 
by fome diforders it is rendered very acrid. On viewing 
the blood wfith a microfcope, whilft it circulates in the 
veins, the globules are obferved to be elaftic, fo as to 
change and recover their figure. Mr. Hewfon fays they 
are not fpherical, but altuofl flat. The ufe of the glo¬ 
bules in the blood l'eems chiefly to be for the prefervation 
of heat in the body ; and that of the ferum for nutrition, 
and by the various Accretions from it to moiften the feveral 
furfaces in the body, to preferve the flexibility of the fo- 
lids, See. A due proportion of the refpeftive parts of 
the blood is neceflary to health ; a redundance of the glo¬ 
bules difpofes to acute fevers, imflammations, &c. and 
their deficiency, to many chronica! diforders. As to the 
red colour of the blood, Dr. Hunter thinks it is chiefly 
owing to the degree to which it is condenfed ; but moll 
Writers attribute it to the acid which it receives from the 
air in the lungs. Dr. Cullen fays, that the mafs of blood 
is every where an heterogeneous aggregate, confiding 
chiefly and efpecially of red globules, gluten, and ferofity 5 
and, if it fnould be alleged that there are other matters pre- 
fent, that they may be confidered as portions of thefe 
three principal parts, For the medical properties, and 
circulationoftheblood, fee Anatomy, vol. i. p. 607-609; 
and for the chemical analyfis, fee Chemistry. 
That life is a property of the blood, was firft broached 
by the celebrated Harvey, the difeoverer of the circula¬ 
tion : but in this he was never much followed ; and the 
hypothefis itfelf was laid afide and neglefted, until it was 
revived by the late Mr. John Hunter, profeifor of anato¬ 
my in London. This gentleman fupports his opinion by 
the following arguments : The blood, he fays, unites liv¬ 
ing parts, in fome circumfiances, as certainly as the yet 
recent juices of the branch of one tree unite it with that 
of another. Were either of thefe fluids to be confidered 
as extraneous or dead matters, they would aft as ftimuli, 
and no union would take place in the animal or vegetable 
kingdoms. This argument Mr. Hunter eftabliflied by the 
following experiment. Having taken off the tefiicle from 
a living cock, he introduced it into the belly of a living 
l’.en. Many weeks afterwards, upon injecting the liver 
of the lien, lie iniefted the tefiicle of the cock like Wife, 
which had come in contact with the liver, and adhered to 
it. In the nature of things, there is not a more intimate 
connection between life and a lolid, than between life and 
a fluid. For, although we are more accuftomed to conneft 
it with the oiie than the other, yet the only rfeal difference 
which can be fiiewn between a folid and a fluid is, that 
the particles of the one are lefs moveable among them- 
felves than thole of the other. Befides, we often fee the 
fame body fluid in one cafe and folid in another. The 
blood will alfo become vafcular like other living parts. 
Mr. Hunter affirms, that, after amputations, the coagula 
in the extremities of arteries form veflels which may be 
injefted by injecting thefe arteries; and he thought he 
could demonftrate veflels riling from the centre of what 
had been only a coagulum of blood, opening into a ffream 
of circulating blood. If blood be taken from the arm, in 
the 1110ft intenfe cold which the human body can bear, it 
raifes the thermometer to the fame height as blood taken 
in the mod fultry heat. This is a ftrong proof of the 
blood’s being alive ; for living bodies alone have the pow¬ 
er of refilling great degrees both of heat and cold, and of 
maintaining in almoft every fituation, while in health, 
that temperature which vve diftinguilh by the name of ani¬ 
mal heat. Blood is likewife capable of being afted upon 
by a ftimulus; for it coagulates from expofure, as cer¬ 
tainly as the cavities of the abdomen and thorax inflame 
from the fame caufe. The more it is alive, that is, the 
more the animal is in health, it coagulates the fooner on 
expofure ; and the more it has loft of its living principle, 
as in the cafe of violent inflammations, the lefs is it fenfi- 
ble to the ftimulus produced from its being expofed, and it 
coagulates the later. We may likewife obferve, that the 
blood preferves life in different parts of the body. When 
the nerves going to a part are tied or cut, the part be¬ 
comes paralytic, and lofes all power of motion; but it does 
not mortify. If the artery be cut, the part dies, and 
mortification enfues. What keeps it alive in the firft cafe?, 
nothing but the living principle, which alone can keep 
it alive ; and this phenomenon is inexplicable on any 
other fuppolition, than that the life is contained in the 
blood. Another argument is drawn by Mr. Hunter from 
a cafe of a fraftured os humeri. A man was brought into 
St. George’s hofpital fora fimple fracture of the arm, 
and died about a month after the accident. As the bones 
had not united, Mr. blunter injefted the arm after death. 
He found that the cavity between the extremities of tlie 
bones was filled up with blood which had coagulated. 
This blood was become full of veflels ; in fome places 
very much fo. He does not maintain that all coagulated 
blood becomes vafcular: and indeed the reafon is obvious; 
for it is often thrown out and coagulated in parts where its 
becoming vafcular could anfvver no end in the fyftem : as, 
for example, in the cavities of aneurifmal facs. If it be 
fuppofedj 
