I commenced this Address by asking you to follow me in an attempt to
trace the path which has been followed by a scientific idea, in its long
and slow progress from the position of a probable hypothesis to that
of an established law of nature. Our survey has not taken us into very
attractive regions; it has lain, chiefly, in a land flowing with the
abominable, and peopled with mere grubs and mouldiness. And it may
be imagined with what smiles and shrugs, practical and serious
contemporaries of Redi and of Spallanzani may have commented on the
waste of their high abilities in toiling at the solution of problems
which, though curious enough in themselves, could be of no conceivable
utility to mankind.
Nevertheless, you will have observed that before we had travelled very
far upon our road, there appeared, on the right hand and on the left,
fields laden with a harvest of golden grain, immediately convertible
into those things which the most solidly practical men will admit to
have value--viz., money and life.
The direct loss to France caused by the Pebrine in seventeen years
cannot be estimated at less than fifty millions sterling; and if we
add to this what Redi's idea, in Pasteur's hands, has done for the
wine-grower and for the vinegar-maker; and try to capitalise its value,
we shall find that it will go a long way towards repairing; the money
losses caused by the frightful and calamitous war of this autumn
(1870). And as to the equivalent of Redi's thought in life, how can we
overestimate the value of that knowledge of the nature of epidemic
and epizootic diseases, and consequently of the means of checking, or
eradicating them, the dawn of which has assuredly commenced?
Looking back no further than ten years, it is possible to select
three (1863, 1864, and 1869) in which the total number of deaths from
scarlet-fever alone amounted to ninety thousand. That is the return of
killed, the maimed and disabled being left out of sight Why, it is to be
hoped that the list of killed in the present bloodiest of all wars will
not amount to more than this! But the facts which I have placed before
you must leave the least sanguine without a doubt that the nature and
the causes of this scourge will, one day, be as well understood as
those of the Pebrine are now; and that the long-suffered massacre of our
innocents will come to an end.
And thus mankind will have one more admonition that "the people perish
for lack of knowledge"; and that the alleviation of the miseries, and
the promotion of the welfare, of men must be sought, by those who will
not lose their pains, in that diligent, patient, loving study of all the
multitudinous aspects of Nature, the results of which constitute exact
knowledge, or Science.