A treatise on chemistry. Vol. 1, The non-metallic elements / by Sir H.E. Roscoe & C. Schorlemmer ...
- Henry Enfield Roscoe
- Date:
- 1881
Licence: Public Domain Mark
Credit: A treatise on chemistry. Vol. 1, The non-metallic elements / by Sir H.E. Roscoe & C. Schorlemmer ... Source: Wellcome Collection.
Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.
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![rapid whirling motion, and this cannot take place in a closed space. However false from our present position we see the phlogistic theory iu certain directions to be; and although we may now believe that the extension and corroboration of the positive views enunciated by Hooke and Mayow might have led to a recognition of a true theor}^ of chemistry more speedily than the adoption of the theory of phlogiston, we must admit that its rapid general adoption showed that it supplied a real want. It was this theory which for the first time established a common point of view from which aU chemical changes could be observed, enabling chemists to introduce something like a system by class- ing together phenomena which are analogous and are probably ])roduced by the same cause, for the first time making it pos- sible for them to obtain a general view of the whole range of chemical science as then known. It may appear singular that the meaning of the fact of the increase of weight which the metals undergo on heating, which had been proved by Boyle and others, should have been whoUy ignored by Stahl, but we must remember that he considered their form rather than their weight to be the important and character- istic property of bodies. Stahl also, perhaps independently, arrived at the same con- clusion which Boyle had reached, concerning the truth of the existence of a variety of elementary bodies, as opposed to the Aristotelian or Paracelsian doctrine, and the influence which a clear statement of this gTeat fact by Stahl and his pupils— amongst whom must be mentioned Pott (1692—1777) and Marggraf (1709—1783)—exerted on the progress of the science was immense. It is only after Stahl's labours that a scientific chemistry becomes, for the first time, possible. The essential difference between the teaching of the science then and now being that the phenomena of combustion were then believed to be due lo a chemical decomposition, phlogiston being supposed to escape, whilst we account for the same phenomena now by a chemical combination, oxygen or some element being taken up. Thus Stahl prepared the Avay for the birth of modern chemis- try. It was on August 1st, 1774, that Joseph Priestley dis- covered oxygen gas. Between the date of the establishment of the phlogistic theory by Stahl, and of its complete overthrow by Lavoisier, many distinguislied men helped to build up the new science—Black.](https://iiif.wellcomecollection.org/image/b21449016_0030.jp2/full/800%2C/0/default.jpg)
