though this was not possible to the things killed
by God." The burning of such substances as wood, wax, oil, etc., was
also looked upon as the same "killing" process, and the fact that the
alchemist was unable to revivify them was regarded as simply the lack of
skill on his part, and in no wise affecting the theory itself.

But the iconoclastic spirit, if not the acceptance of all the teachings,
of the great Paracelsus had been gradually taking root among the better
class of alchemists, and about the middle of the seventeenth century
Robert Boyle (1626-1691) called attention to the possibility of making
a wrong deduction from the phenomenon of the calcination of the metals,
because of a very important factor, the action of the air, which was
generally overlooked. And he urged his colleagues of the laboratories to
give greater heed to certain other phenomena that might pass unnoticed
in the ordinary calcinating process. In his work, The Sceptical Chemist,
he showed the reasons for doubting the threefold constitution of matter;
and in his General History of the Air advanced some novel and carefully
studied theories as to the composition of the atmosphere. This was an
important step, and although Boyle is not directly responsible for the
phlogiston theory, it is probable that his experiments on the atmosphere
influenced considerably the real founders, Becker and Stahl.

Boyle gave very definitely his idea of how he thought air might be
composed. "I conjecture that the atmospherical air consists of three
different kinds of corpuscles," he says; "the first, those numberless
particles which, in the form of vapors or dry exhalations, ascend
from the earth, water, minerals, vegetables, animals, etc.; in a word,
whatever substances are elevated by the celestial or subterraneal heat,
and thence diffused into the atmosphere. The second may be yet more
subtle, and consist of those exceedingly minute atoms, the magnetical
effluvia of the earth, with other innumerable particles sent out from
the bodies of the celestial luminaries, and causing, by their influence,
the idea of light in us. The third sort is its characteristic and
essential property, I mean permanently elastic parts. Various hypotheses
may be framed relating to the structure of these later particles of the
air. They might be resembled to the springs of watches, coiled up and
endeavoring to restore themselves; to wool, which, being compressed,
has an elastic force; to sl