Physical chemistry for physicians and biologists / by Ernst Cohen ; authorized translation from the German by Martin H. Cohen.
- Ernst Cohen
- Date:
- 1903
Licence: Public Domain Mark
Credit: Physical chemistry for physicians and biologists / by Ernst Cohen ; authorized translation from the German by Martin H. Cohen. Source: Wellcome Collection.
60/360 page 46
![observations of Nageli* upon oligodynamical phenom- ena, which were not made public until Schwendener pub- lished them after Nageli’s death. Nageli found that exceedingly small amounts of metals (or metallic salts) dissolved in water have a distinctively toxic effect upon certain living cells. It was found, for example, that spirogyra cells are poi- soned by water in which one part of copper is present in 1000 million parts of water. These experiments have been repeated and corroborated by Cramer,f Dehérain and Demoussy,{ and by Coupin.§ The question as to whether these facts, as some affirm, give support to the teachings of homceopathy may for the time being be set aside.|| 2. The catalytic activity of the platinsol is often greatly decreased through the addition of even very smal] amounts of electrolytes (salts, acids, etc.). Thus the velocity constant which in a given case had been 0.023 originally, fell to 0.015 when 5,55 mol Na,HPO, was added to each litre of the H,O, solution. When the experiment was repeated several days later with the same solution of platinum, which had in the mean time remained in contact with the sodium phosphate, it was found that the constant had decreased still more (0.011). This progressive loss in the activity of the catalytic * Neue Denkschriften der allgemeinen schweizerischen Gesell- schaft für die gesammten Naturwissenschaften 33, Abt. 1 (1893). See also H. de Varigny, Revue Scientifique 30, 2, Sept. 1893. + Ibid. t Compt. rend. 137, 523 (1901). § Ibid. 132, 645 (1901). || v. d. Stempel, Geneeskundige Courant (Amsterdam); April 14, 21, and May 5, 1901.](https://iiif.wellcomecollection.org/image/b32861631_0060.jp2/full/800%2C/0/default.jpg)
