545 
ON THE IDENTITY OE PLEURO-PNEUMONIA AND RUBEOLA. 
By W. Thomson, M.R.C.S., &c. 
(Read before the Medical Society of Victoria.) 
Mr. President and Gentlemen, —The havoc among 
our herds caused by pleuro-pneumonia gives great interest 
to every circumstance connected with the malady. This in¬ 
terest is deepened by the mystery surrounding many things 
concerning its history—as to origin, nature, preventibility, 
or treatment. The alarm of the past has not subsided, but is 
continued into anxiety for the future ; for the ravages of the 
disease are nearly as severe as ever, and opinions nearly as 
much divided about the most efficient means of staving; them. 
It becomes, in consequence, of the utmost importance to elu¬ 
cidate if possible the points about which these differences 
exist, so that concerted efforts may be directed with the pre¬ 
cision only practicable after a full and exact knowledge is 
gained of the disease they would aim to exterminate. To this 
end it will be even useful to prove a negative; for by show¬ 
ing what the disease is not, w 7 e come by so much the nearer, 
in the process of elimination, to the discovery of what it is. 
H ow'much more, then, if w 7 e can determine a positive, and give 
the disease its proper place in nosology ? To show that this is 
possible is the design of the few following preliminary obser¬ 
vations. Preliminary, I repeat, because they are necessarily 
introductory and cursory, and made more with a view to lead 
discussion into a new r direction than to deal exhaustively with 
the subject. At a future time this also may be systematically 
attempted, in order to elaborate more fully the view's which I 
now proceed to lay before you. To know that the disease 
has not hitherto been satisfactorily defined, it is enough to 
refer to any author wffio has treated of the question. By 
much laborious inquiry, close observation, and keen discus¬ 
sion by men of the highest order of talent, many facts rela¬ 
tive to the affection have been established beyond further 
dispute ; but by the same men it is with equal candour ad¬ 
mitted, that its true nature and affinities still baffle research, 
and remain among the questiones vexatce. The name originally 
given to the disease, adopted as descriptive of the most 
prominent symptom, has long lost its significance, is now a 
misnomer, and is retained conditionally, as involving nothing 
theoretical, until a true one be suggested. No one has been 
as yet offered as a substitute upon scientific reasons; but the 
term which merely denotes, faithfully it is true, one of the 
