Colloids and the ultramicroscope : a manual of colloid chemistry and ultramicroscopy / tr. by Jerome Alexander.

  • Zsigmondy, Richard.
Date:
1909
Catalogue details

Licence: Public Domain Mark

Credit: Colloids and the ultramicroscope : a manual of colloid chemistry and ultramicroscopy / tr. by Jerome Alexander. Source: Wellcome Collection.

Provider: This material has been provided by the Gerstein Science Information Centre at the University of Toronto, through the Medical Heritage Library. The original may be consulted at the Gerstein Science Information Centre, University of Toronto.

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    cipitating salts, may admit of a similar explanation. (P. 221). The hardness of the. crystalloid, with its crystalline planes and angles, is replaced in the colloid by a degree of softness, with a more or less rounded outline. The water of crystallization is represented by the water of gelatination. The water in gelatinous hydrates is aptly described by M. Chevreul as retained by 'capillary affin- ity/ that is, by an attraction partaking both of the phy- sical and chemical character. (P. 222). Graham, at the conclusion of his important work, gives an explanation of osmosis, which in the main agrees with the views of Liebig, published some time previously. The contents of another valuble work of Graham will for the most part be given in the'author's own words. On the Properties of Silicic Acid and other Analogous Colloidal Substances By THOMAS GRAHAM, F.R.S., Master of the Mint (Received June 16, 1864) l PRELIMINARY NOTICE The prevalent notions respecting solubility have been derived chiefly from observations on crystalline salts, and are very imperfectly applicable to the class of colloidal substances. Hydrated silicic acid, for instance, when in the soluble condition, is, properly speaking, a liquid body, like alcohol, miscible with water in all proportions. We have no degrees of solubility to speak of with respect to silicic acid, like the degrees of solubility of a salt, unless it be with reference to silicic acid in the gelatinous con- Thomas Graham, Proceedings of the Royal Society, June 16, 1864. (Also Pogg, Ann., 1864, Vol. CXXIII, pp. 529-541.)