Volume 4
A history of science / by Henry Smith Williams ... assisted by Edward H. Williams.
- Henry Smith Williams
- Date:
- 1904
Licence: Public Domain Mark
Credit: A history of science / by Henry Smith Williams ... assisted by Edward H. Williams. Source: Wellcome Collection.
43/376 page 25
![gen, baryta, and chlorine, the last of far greater im¬ portance, at least commercially, than the real object of his search. In speaking of the experiment in which the discovery was made he says: “When marine (hydrochloric) acid stood over man¬ ganese in the cold it acquired a dark reddish-brown color. As manganese does not give any colorless solu¬ tion without uniting with phlogiston [probably meaning hydrogen], it follows that marine acid can dissolve it without this principle. But such a solution has a blue or red color. The color is here more brown than red, the reason being that the very finest portions of the manganese, which do not sink so easily, swim in the red solution; for without these fine particles the solu¬ tion is red, and red mixed with black is brown. The manganese has here attached itself so loosely to acidum salts that the water can precipitate it, and this precipi¬ tate behaves like ordinary manganese. When, now, the mixture of manganese and spiritus salis was set to digest, there arose an effervescence and smell of aqua regis.” 6 The “ effervescence ’ ’ he refers to was chlorine, which he proceeded to confine in a suitable vessel and ex¬ amine more fully. He described it as having a “quite characteristically suffocating smell,” which was very offensive. He very soon noted the decolorizing or bleaching effects of this new product, finding that it decolorized flowers, vegetables, and many other sub¬ stances. Commercially this discovery of chlorine was of enor¬ mous importance, and the practical application of this](https://iiif.wellcomecollection.org/image/b31359486_0004_0045.jp2/full/800%2C/0/default.jpg)
