280 
P A T H O 
This definition of Dr. Good’s is extremely vague. It 
is very difficult, however, to make any arrangement of 
cachexies in our prefent ftate of knowledge without ma¬ 
ny faults j but, at all events, fome of the difeafes already 
mentioned might be referred to morbidity of the blood- 
veffels ; and certainly dropfy has little to do with depra¬ 
vity of the blood as a primary caufe. We muft confefs, 
however, that this is not the cafe of Plethora, Haemor- 
rhagies, Paffiva, Cyrtofis, Porphyra, and fome others. 
We have already exprefied our opinion that many dif¬ 
eafes are referrible to morbidity in the blood : and, after 
long and unwarrantable difregard of this important faff, 
our contemporaries are now returning to the inveftiga- 
tion of the nature of the blood in difeafe. Their labours 
have hitherto been little fuccefsful ; and indeed fcarcely 
any thing can be ftated with certainty as to the ftate of 
the blood in the majority of difeafes, nor in any of them 
are we able to trace tbofe minute changes on which the¬ 
rapeutical agents would be fafely fet in adKon. It feems 
pretty clear that all material changes in the blood muft 
be a work of time. The changes which a fudden altera¬ 
tion in the blood would induce in the conlradtility of the 
vafcular and fenfibility of the nervous fyftems would be 
fuch, that death, or at all events extreme febrile com¬ 
motion, muft occur. Moreover, all unnatural matters 
in the blood would, under fuch circumftances, be carried 
off by the fecretions; and thus the fanguineous fluid 
would return to its natural condition. Blood being 
folely derived from food and air, it is to thefe agents we 
muft look for its alterations. As the former can operate 
only by producing a greater or lefs degree of oxygenation 
in the blood, and as cachedfic difeafes are not extraor¬ 
dinarily manifefted in fituations where bad air is prefent, 
we fhould probably be right in referring cachexis to the 
ill effedts of particular food? Indeed deficiency or bad 
quality of food and drink is evidently the caufe of a very 
large proportion of cachedtic maladies, and a ferious 
fource of aggravation to them all. In the natural or 
healthy ftate, indeed, we have very clear evidence, that 
unhealthy chyle is not formed in confequence of one or 
two improper meals; but when, from a long-continued 
ufe of fubftances irritating to the alimentary canal, from 
a reftridtion to one particular kind of food, or from pre¬ 
vious difeafe in the abforbent or aifimulating veflels, 
blood is flowly and imperceptibly produced of an unna¬ 
tural quality, we fhould be prepared to meet with a cor- 
refponding change in the contractility of the containing 
veflels; we ftiould expeCt alfo to find the fecretion flowly 
deranged, and, as the difeafe advanced, the nervous fyf- 
tem debilitated. The changes which the blood under¬ 
goes is perhaps very various in different difeafes; but 
we know little of them. We may remark, however, that 
in all cachedtic difeafes (properly fo named), the change 
in the blood diminifties the contractile power of the fan¬ 
guineous fyftem. Now', it having been proved by expe¬ 
riment, that the quantity of fibrine, and confequently the 
degree of coagulation, is in direCt ratio to the force of 
the arterial contractions, we fhould naturally expeCt to 
find the blood containing an unufual proportion of fe- 
rum, and more flow in its concretion, in cacheCtic dif¬ 
eafes, fince in them fymptoms of arterial debility are for 
the moll part unequivocal. It is only in this view of the 
fubjeCl that the firft genus o£ this order, viz. Plethora, 
can be allowed to exift ; for, from what has been before 
ftated with regard to the dependance of the blood-veflels 
on the nerves, of the nerves on the veflels, and of the 
veflels on the blood, plethora, exifting while thefe par¬ 
ticular ftrudtures retained their natural properties, muft 
inevitably terminate in local inflammation. This order 
contains fifteen genera. 
Genus I. Plethora, [from to fill.] Fulnefs of 
blood. Generic characters—Complexion florid ; veins 
diftended; undue fenfe of heat and fulnefs; oppreffion 
LOGY. 
of the head, cheft, or other internal organ. There are 
two very diftinCt fpecies. 
i. Plethora entonica, fanguine- plethora. This firft 
fpecies is rarely feen as a difeafe. It is probably a fre¬ 
quent forerunner of all the fpecies of PyreCtica and Phlo- 
gotica, but exifts in various degrees in different habits, 
and in many perfons without manifefting fcarcely any 
fymptoms of indifpofition. The change ufually obferved 
in the blood is an increafe of coagulation, and in the 
rednefs of its colour. 
a. Plethora atonica, or ferous plethora, is a difeafe in 
which much change is induced in the ftate of blood. 
This change confifts in an undue proportion of ferum, 
and a deeper hue than ordinary. The pulfe is full, fre¬ 
quent, and feeble ; the mental adtions languid ; dullnefs 
and lownefs of fpirits being often met with. The figure 
is often plump, but inexprelfive, fuch as is vulgarly called 
dead fat; and the urine coagulates on the application of 
heat. 
The treatment of plethora is fufficiently obvious. The 
firft fpecies, being the forerunner of inflammation or in¬ 
flammatory dropfy, will require brifk purging and bleed¬ 
ing, and a fpare and vegetable diet. In the fecond fpe¬ 
cies, the fame indication of reducing the bulk of the 
blood is to be kept in view ; but, as free bleeding dimi¬ 
nifties rapidly the tone of the fyftem, and as the vital 
powers are evidently in a very low ftate, we muft proceed 
with the utmoft caution ; and, contrary to what is prac- 
tifed in inflammations, (where our objeCt is to diminifh 
the exceflive adtion of the heart rather than the quantity 
of blood,) we ftiould in ferous plethora bleed very fre¬ 
quently, but in fmall quantities at a time. An altera¬ 
tion ftiould be made in the diet, which, in the majority 
of cafes, fhould gradually become fparing. The treat¬ 
ment of dyfpepfia united with the chronic hepatitis (dif¬ 
eafes ufually combined with the ferous plethora) fhould 
be purfued, and the kidneys excited by means of diure¬ 
tics. 
Plethora, in one or other of its fpecies, is ufually 
found as an almoft-univerfal fymptom in hemorrhage 
and dropfy. 
Genus II. Harnorrhagia, [from a:/xa, blood, and ptu, 
to flow.] Hemorrage; flux of blood from an organ with¬ 
out external violence. There are three fpecies, befides 
varieties. 
i. Haemorragia adtiva, adtive hemorrhage: accompa¬ 
nied with increafed vafcular action ; blood florid and te¬ 
nacious. 
Active hemorrhages are caufed by all circumftances 
capable of inducing an increafed momentum in the af- 
fedted part, or in the fyftem generally. 
The immediate or proximate caule of an adtive hae¬ 
morrhage is the rupture of a blood-veflel, where the blood 
flows till, by the permanent contradtion of the broken 
artery, or a coagulum, it is mechanically reftrained. 
This retention is much more readily effedted if the heart 
is quiefeent. 
Adtive hemorrhages we muft confider as febrile dif¬ 
eafes of an inflammatory kind. They are defined by 
Dr. Cullen, Pyrexia, with an effufion of blood indepen¬ 
dent of external violence ; and the blood drawn having 
an inflammatory appearance. Adtive hemorrhages 
chiefly occur in full plethoric habits, moft frequently in 
the fpringand in the early months of fummer. Previous 
to the fever which uftiers in the difeharge, fome general 
fulnefs and uneafinefs is felt, with a load on the parts 
from whence the hemorrhage will flow. The topical 
heat, fwelling, or itching, is fometimes confiderable. A 
fliort rigor which follows is relieved by the ufual heat, 
and the hemorrhage foon comes on during this hot fir. 
After fome time the difeharge and the fever both ceafe y 
but every fpontaneous hemorrhage has a tendency to re¬ 
cur; and, if this recurrence happens more than once, 
after 
