Volume 2

An essay on chemical statics : with copious explanatory notes, and an appendix on vegetable and animal substances / faithfully translated from the original French of C. L. Berthollet ... by B. Lambert.

  • Lambert Bernard, 1738-1813.
Date:
1804
Catalogue details

Licence: Public Domain Mark

Credit: An essay on chemical statics : with copious explanatory notes, and an appendix on vegetable and animal substances / faithfully translated from the original French of C. L. Berthollet ... by B. Lambert. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    487/516 (page 477)
    Solution. The colour of the precipitate is changed from white to grey. The oxide is not, however, yet deprived of all the acid with which it was combined, for by dissolving it in nitric acid diluted with water, it renders nitrate of silver turbid. If an excess of alkali is put into the muriate which is precipitated, the excess dissolves a little oxide of tin : the liquor separated from the precipitate, and saturated with muriatic acid, is precipitated brown by the hidro-sulphuret of pot-ash, and precipitates the oxi- genated muriate of mercury white : but when instead of separating the precipitate from the supernatant liquor, the action of the alkali is assisted by heat, it carries off the acid of the precipitate, which becomes a defep grey. By suffering the alkali to act in the cold, there is only a slow and partial decomposition. The reagents do not indicate any change in the degree of oxidation of the oxide, freed, in this manner, from every combination. Proust observed* that wffien muriate of tin was de- composed by pot-ash, this alkali redissolved rll the precipitate which was formed, if a sufficient excess was made use of, and that, in this solution of oxide of tin bv pot-ash, a sort of metallic cauliflower (choujieur metallique) was formed in a short time, which he took for revivified tin, after having ascertained that the portion of oxide wdiich remained in solution had no longer the power ofchanoino- corrosive sublimate. It is lcnownf that pot-ash dissolves highly oxided tin more readily than that which is but little so : now, the united affinities of oxide of tin for a new quantity of oxigen, and of pot-ash for the metal brought to this state, are sufficient to destroy the uniformity of its oxidation. One part of the oxide forms a permanent * Recherch. sur l’Etain. Journ. de Phys. Fruct. An. VIII f Obs. sur l’acide de l’Etain, par Guyton. Ann. de Chim Tom.XXIV. combination