Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 1, 1802).djvu/538

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C H E
C H E

debility, a longer course of evacuation, than most other medicines of tins kind, yet it cannot be used in every case, where a simple chalybeate is indicated. There are constitutions naturally languid, or debilitated by disease, so that they may be materially injured by a long-continued operation on the bowels. These saline waters, nevertheless, possess the peculiar advantage, that they may be used without any preparation. No other medicine is required, during their use, except the occasional addition of crystallized salts, of the same nature, where the water is not sufficiently laxative for costive habits; and likewise the use of the warm bath, particularly in cutaneous disorders.

The season for drinking Cheltenham water, is during the summer months; and, if possible, it should always be taken at the fountain head, and never kept long exposed to the air. It may, however, be cautiously warmed in close vessels, if, in a cold state, it should be offensive to the stomach of the patient.—Different circumstances will necessarily vary the extent of the dose; for which, half a pint of water is generally sufficient; and, if repeated three or four times, at proper intervals during the day, it seldom fails to produce an aperient effect.

Among the separate treatises published on this subject, we believe the most complete, though, perhaps, not the latest, is, Dr. J. Smith's "Observations on the use and abuse of the Cheltenham Waters; with remarks on different saline compositions;" published in 1784.

CHEMISTRY is one of the most important branches of Physics, or Natural Philosophy; and, though not easily defined, we shall attempt the following short analysis: The science of chemistry implies the knowledge of the component parts of bodies, whether animal, vegetable, or mineral: that is, the art of decomposing compound substances; re-producing them, if possible; and ascertaining their physical properties, and relations to each other, as well as of determining, with accuracy, the affinity subsisting between simple earths, metals, &c.—Others have defined chemistry to signify the study of such phenomena, or properties of bodies, as are discoverable, by variously mixing them, or by exposing them to different degrees of heat, in order to enlarge our knowledge of Nature, and improve the useful arts.—There is no doubt that the changes taking place in bodies, are caused by motion, which, particularly by means of heat, is infused into, and perpetually agitates, the vast corporeal system. The chemist, therefore, inquires into the causes of this motion, and by what means it may be generated, diverted, or checked. But, as these impulsive powers are not within the reach of reason unassisted by the observation of effects obvious to the senses, he endeavours to ascertain their nature, by carefully attending to the different action of bodies, when placed in contact with others, either in a dry or fluid state, or submitted to the operation of fire; from which he has discovered, more by accident than design, many hidden processes of Nature.

The extensive utility of chemical science, to a commercial and manufacturing nation, in almost every branch of trade, must be evident

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