, and with such success
that the "angelic doctor" remains today the supreme human authority of
the Roman Catholic Church.

(22) Bibliotheca Chemica, 1906, Vol. I, p. 15.

A man of much greater interest to us from the medical point of view is
Roger Bacon and for two reasons. More than any other mediaeval mind he
saw the need of the study of nature by a new method. The man who could
write such a sentence as this: "Experimental science has three great
prerogatives over other sciences; it verifies conclusions by direct
experiment; it discovers truth which they never otherwise would reach;
it investigates the course of nature and opens to us a knowledge of the
past and of the future," is mentally of our day and generation. Bacon
was born out of due time, and his contemporaries had little sympathy
with his philosophy, and still less with his mechanical schemes and
inventions. From the days of the Greeks, no one had had so keen an
appreciation of what experiment meant in the development of human
knowledge, and he was obsessed with the idea, so commonplace to us, that
knowledge should have its utility and its practical bearing. "His chief
merit is that he was one of the first to point the way to original
research--as opposed to the acceptance of an authority--though he
himself still lacked the means of pursuing this path consistently. His
inability to satisfy this impulse led to a sort of longing, which is
expressed in the numerous passages in his works where he anticipates
man's greater mastery over nature."(23)

(23) Dannemann: Die Naturwissenschaften in ihrer Entwicklung und
in ibrem Zusammenhange, Leipzig, 1910, Vol. I, pp. 278-279.

Bacon wrote a number of medical treatises, most of which remain in
manuscript. His treatise on the "Cure of Old Age and the Preservation of
Youth" was printed in English in 1683.(24) His authorities were largely
Arabian. One of his manuscripts is "On the Bad Practices of Physicians."
On June 10, 1914, the eve of his birth, the septencentenary of Roger
Bacon will be celebrated by Oxford, the university of which he is the
most distinguished ornament. His unpublished MSS. in the Bodleian will
be issued by the Clarendon Press (1915-1920), and it is hoped that his
unpublished medical writings will be included.

(24) It may be interesting to note the three causes to which he
attributes old age: "As the World waxeth old, Men grow old with
it: not by reason of the Ag