Introductory address to the course of medical lectures : at Georgetown College, November 3, 1862 / by Silas L. Loomis.

  • Loomis, Silas L. (Silas Lawrence), 1822-1896.
Date:
1862
Catalogue details

Licence: Public Domain Mark

Credit: Introductory address to the course of medical lectures : at Georgetown College, November 3, 1862 / by Silas L. Loomis. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

    17/22
    This condition is general. A chemical building up absorbs surrounding vibrating particles of setheria as an element of the new compound, and whenever this runs down, retheria is liberated, and through some manifestation exposes is pres- ence. The law, therefore, that all the physical properties of a body depend upon its chemical constitution, appears to be true in its broadest application. Water, ice, and steam are as much different compounds as the atmosphere, laughing gas, and aqua fortis. A class of phenomena, called Allotropism, to which no satisfactory exposition has been given, is very closely allied to the above. Indeed, there is no good reason known why water may not be called an allotropic condition of ice. The phenomena are so closely related that it is not easy to say wherein the difference consists. Ice, without any additional element, changes its properties; in the same manner sulphur, without any additional element, changes its properties. In one case it is called allotropism, and in the other a change of form. Perhaps we shall be able to understand better the difference if we translate the Greek word Allotropism. It means to change to another. The difference may be that the one class of phenomena is a common occurrence, while the other is confined to the lab- oratory. The only real difference is that in one case the change of form takes place in compound bodies, and the allotropic condition in elementary or simple bodies. Among the elementary bodies are chlorine, phosphorus, sulphur, &c, that under certain conditions, without the addition of any Materia whatever, assume entirely different properties, to such an extent as to lose their identity. They are then said to be in an allotropic condition, oxygen becomes ozone, sulpher loses its prop- erties and becomes more like gutta percha, phosphorus is no longer identified, chlorine assumes new properties, &c. It is a fact worthy of notice in regard to these remarkable changes, that no elementary body assumes its allotropic form, without being exposed to JEtheria, either in a condensedform, or in an intensely vibrating or disturbed state. It is equally true that no compound