A History of Science-4 [1]
to the calcined product. To the alchemist this was "mortification" and "revivification" of the metal. For, as pointed out by Paracelsus, "anything that could be killed by man could also be revivified by him, although 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 slender wires of different substances, consistencies, lengths, and thickness; in greater curls or less, near to, or remote from each other, etc., yet all continuing springy, expansible, and compressible. Lastly, they may also be compared to the thin shavings of different kinds of wood, various in their lengths, breadth, and thickness. And this, perhaps, will seem the most eligible hypothesis, because it, in some measure, illustrates the production of the elastic particles we are considering. For no art or curious instruments are required to make these shavings whose curls are in no wise uniform, but seemingly casual; and what is more remarkable, bodies that before seemed unelastic, as beams and blocks, will afford them."[1]
Although this explanation of the composition of the air is most crude, it had the effect of directing attention to the fact that the atmosphere is not "mere nothingness," but a "something" with a definite composition, and this served as a good foundation for future investigations. To be sure, Boyle was neither the first nor the only chemist who had suspected that the air was a mixture of gases, and not a simple one, and that only certain of these gases take part in the process of calcination. Jean Rey, a French physician, and John Mayow, an Englishman, had preformed experiments which showed conclusively that the air was not a simple substance; but Boyle's work was better
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 slender wires of different substances, consistencies, lengths, and thickness; in greater curls or less, near to, or remote from each other, etc., yet all continuing springy, expansible, and compressible. Lastly, they may also be compared to the thin shavings of different kinds of wood, various in their lengths, breadth, and thickness. And this, perhaps, will seem the most eligible hypothesis, because it, in some measure, illustrates the production of the elastic particles we are considering. For no art or curious instruments are required to make these shavings whose curls are in no wise uniform, but seemingly casual; and what is more remarkable, bodies that before seemed unelastic, as beams and blocks, will afford them."[1]
Although this explanation of the composition of the air is most crude, it had the effect of directing attention to the fact that the atmosphere is not "mere nothingness," but a "something" with a definite composition, and this served as a good foundation for future investigations. To be sure, Boyle was neither the first nor the only chemist who had suspected that the air was a mixture of gases, and not a simple one, and that only certain of these gases take part in the process of calcination. Jean Rey, a French physician, and John Mayow, an Englishman, had preformed experiments which showed conclusively that the air was not a simple substance; but Boyle's work was better