SEP ZS lege 
NATURAL SCIENCE 
A Monthly Review of Scientific Progress 
No. 79—Vo.t. XIII—SEPTEMBER 1898 
NOTES AND COMMENTS 
‘VACCINATION 
Ir is the plain duty of every scientific journal at the present crisis 
in the history of vaccination, to put before its readers a clear state- 
ment of the facts at issue. But it must not be forgotten that two 
very distinct questions are involved: the efficacy of, vaccination is 
one thing, the expediency of compulsory vaccination is another. 
The efficacy of vaccination in preventing small-pox is a scientific 
fact, established by evidence as clear as any in the range of our 
knowledge. We do not, nowadays, pause to argue with a man who 
says the earth is flat. No level-headed person with any capacity 
for weighing evidence doubts that vaccination, efficiently performed, 
affords an almost absolute protection against small-pox for a term 
of five to ten years, according to the natural susceptibility of the 
individual—that after this period the protection gradually fades, 
though, in most cases, persisting in some degree throughout life—and 
that it may be renewed by re-vaccination, Vaccination has been 
the main agent, in this and other countries, in reducing small-pox 
mortality to its present low level, and it has done so by abolishing 
the excessive infant mortality from the disease which prevailed in 
pre-vaccination times. Statistics show clearly enough that small- 
pox mortality in any country diminishes strictly in proportion to 
the extent to which vaccination is carried out. In proportion as 
re-vaccination is universal, small-pox is reduced to the vanishing 
point. What mortal man could do in discrediting vaccination was 
done in the minority report of the recent vaccination commission, 
an ingenious and plausible piece of special pleading, which was 
absolutely torn to pieces by Dr M‘Vail in his paper read before the 
Epidemiological Society shortly after. 
We take the propositions we have mentioned above as axioms, 
and we are not concerned to defend them in this place. Their 
scientific basis rests on the principle that the virus of an infectious 
disease may be so diminished in effect, by passage through a 
relatively insusceptible animal, as to produce a mitigated form of 
the affection, capable, nevertheless, of conferring protection against 
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