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ON THE NOSOLOGY OF PLEURO-PNEUMONIA. 
of the community. Every new term must be possessed of certain 
qualities before it can be admissible for general adoption. These 
qualities are perspicuity , euphony, and brevity. Without these 
essentials it ought not to be in any way employed. New objects 
or things not previously defined require oftentimes that new terms 
should be invented. These should, however, be as few as pos- 
sible, and all old terms that are well understood ought, as far as 
expressiveness will allow, to be adhered to. 
These remarks have been forced on my mind in the endeavour 
to clearly understand the term now so common, “ pleuro-pneu- 
monia.” This term means, if any thing, that the substance of the 
lung and serous membrane lining the cavity of the chest, and 
covering or enclosting the lung itself, are the seats of disease. 
So far as the term is confined to the disease situate in these parts, 
it is at once expressive and correct. But it is only expressive of 
one form or stage of the disease. This may be frequent, but it is 
certainly not invariably present. Let us look at the symptoms as 
they are described; and what do they indicate 1 The indication is 
very simple : it is nothing more or less than a highly deranged 
state of function, accompanied by a general febrile state of the 
whole body. Every one who has had any experience in the dis- 
ease must be aware that the disease will assume every variety of 
form, according to the peculiar idiosyncrasy of the animal at- 
tacked. It may be true that the larger part of those animals that 
die of this disorder are found to be affected with such a form of 
the disease ; but many cases never shew, at any period during 
the attack, any appearance of the lung affection. It may be con- 
fined to the bowels, the liver, the udder, to dropsical swellings, to 
severe affection of the skin or extremities, or it may be confined 
throughout to derangement of the functions of the brain and nerv- 
ous system. 
The impression conveyed by the term which has unfortunately 
been adopted is an erroneous one. It matters not what particular 
organ requiring treatment peculiar to itself may be the more im- 
mediate seat of the malady ; it is still called by this unhappy mis- 
nomer. For example, a cow is attacked with the peculiar erup- 
tive disease spreading over the whole of the skin, accompanied by 
all the symptoms of low fever, so characteristic of the disease. 
Yet this is still called “ pleuro-pneumonia,” and the same remark 
will apply to any other of the many forms that such a protean dis- 
ease will assume. It will now be apparent how essential it is to 
properly define terms. What would be said of a physician who, 
on being called in to a patient suffering under any of the forms of 
fever, should treat the disease as one affecting the lungs alone ? 
Would not such a man be set down for a blunderer — one unfit to 
