he has traversed many different countries leaving foot-
prints, but he did not intend to explore them; they were
merely along his pathway and the grandeur of his dis-
coveries makes it possible for the history of his mind,
even though reduced to a report, to clothe these adven-
tures with all the air of a romance.

My second reason is that in its details this scientific
life is no less interesting than in its ensemble. As one
may readily conceive, Pasteur encountered many diffi-
culties and many obstacles. These obstacles we recog-
nize more clearly as such, now that they have been
surmounted and we see them behind us. It is interesting
to see how Pasteur outflanked or evaded them. He
employed for that purpose qualities of the first order.
At the same time audacious and prudent, deceiving
himself sometimes even for a long period but being
brought back constantly to the true path by that ex-
acting experimental method of which he has so often
spoken gratefully, he is always worthy of admiration
and worthy also to serve as an example. It is less for
the purpose of making an eulogy than for purposes of
instruction that I have attempted to write his history,
in which I set aside all that relates to the man, that I
may speak only of the savant. I have desired, in the
ensemble as well as in the particulars, to give the genesis
of his discoveries, believing that he has nothing to lose
by this analysis, and that we have much to gain. But
I found the task difficult. It is now for the skeptical
reader to say whether I have succeeded.

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