IDENTITY OF PLEURO-PNEUMONIA AND RUBEOLA. 547 
* 
equally definite affection of the kidneys follows. This 
is invariable. We never find disorder of the lungs, liver, 
or stomach constituting the second stage of scarlatina; if 
the disease be protracted beyond the first stage, it is in the 
form of a renal affection. Renal disease with general dropsy 
without prior scarlatina there may be, but this idiopathic 
form is wholly unlike the specific form, however closely re¬ 
sembling it. Then there is typhoid fever, followed by intes¬ 
tinal ulcerations, with equally unfailing regularity. The fever 
may subside or be subdued by treatment in its first stage, 
but if the second supervene, there is no escape from the in¬ 
evitable enteritic disease. Small-pox has its peculiar sequelae 
in erysipelatous inflammations of cellular, glandular, and 
articular parts, and a peculiar dyspnoea. In measles there is 
the invariable bronchitis, or pneumonia, or pleurisy. Other 
complications, as of the nervous system or digestive organs, 
may be superadded, but the affections of the lungs are never 
absent. Thus, then, we observe that in all these eruptive 
disorders there are two distinct periods, each complete in it¬ 
self, but inseparably related in pathological cause and effect 
to each other. A fatal issue may take place in either stage, 
but such a termination occurs from totally different causes in 
each, or rather the mode of death is different. Then again, 
these periods are never mixed up in the different exanthems; 
nor are the secondary phases altered, nor the morbid states 
substituted the one for the other. The same patient may 
suffer from measles with pneumonia, scarlatina with renal 
dropsy, small-pox with erysipelas, typhoid fever with enter¬ 
itis, all in succession; but no one ever heard, at least, in the 
ordinary course of disease, of renal dropsy after typhoid fever, 
nor ulceration of Peyer’s glands after scarlatina. These facts 
are so well known as to constitute a true pathology, and give 
to this department of physic a fair claim to the exactness of 
a science, whatever may be denied to the therapeutics which 
is endeavoured to be founded upon it. The group of diseases 
so singularly characterised, and having so many striking re¬ 
semblances yet exact specific differences, has received differ¬ 
ent appellations, according as it was wished to signify a theory 
of their common origin, or to describe some pathognomonic 
symptom. Thus they are classed together as zymotic fevers, 
from the supposed origin and cause; or they are termed ex¬ 
anthemata, or eruptive fevers, from the eruption or efflores¬ 
cence on the skin ; or contagious fevers, from their qualities 
of communicability to those susceptible to their poison. 
{To be continued .) 
