e evil and to prevent serious accidents, fires
be lighted and jets of steam used to ventilate the mines--stress being
especially laid upon the idea that the danger in the mines is produced
by "exhalations of metals."

Thanks to men like Valentine, this idea of the interference of Satan
and his minions with the mining industry was gradually weakened, and the
working of the deserted mines was resumed; yet even at a comparatively
recent period we find it still lingering, and among leading divines in
the very heart of Protestant Germany. In 1715 a cellar-digger having
been stifled at Jena, the medical faculty of the university decided
that the cause was not the direct action of the devil, but a deadly gas.
Thereupon Prof. Loescher, of the University of Wittenberg, entered a
solemn protest, declaring that the decision of the medical faculty was
"only a proof of the lamentable license which has so taken possession of
us, and which, if we are not earnestly on our guard, will finally turn
away from us the blessing of God."(281) But denunciations of this kind
could not hold back the little army of science; in spite of adverse
influences, the evolution of physics and chemistry went on. More and
more there rose men bold enough to break away from theological methods
and strong enough to resist ecclesiastical bribes and threats. As
alchemy in its first form, seeking for the philosopher's stone and the
transmutation of metals, had given way to alchemy in its second form,
seeking for the elixir of life and remedies more or less magical for
disease, so now the latter yielded to the search for truth as truth.
More and more the "solemnly constituted impostors" were resisted
in every field. A great line of physicists and chemists began to
appear.(282)

(281) For Loescher's protest, see Julian Schmidt, Geschichte des
geistigen Lebens, etc., vol. i, p. 319.

(282) For the general view of noxious gases as imps of Satan, see
Hoefer, Histoire de la Chimie, vol. i, p. 350; vol. ii, p. 48. For the
work of Black, Priestley, Bergmann, and others, see main authorities
already cited, and especially the admirable paper of Dr. R. G. Eccles on
The Evolution of Chemistry, New York, D. Appleton & Co., 1891. For the
treatment of Priesley, see Spence's Essays, London, 1892; also Rutt,
Life and Correspondence of Priestley, vol. ii, pp. 115 et seq.

II.

Just at the middle of the seventeenth century, and at the very centre
of opposi