Conspectus of the pharmacopoeias of the London, Edinburgh, and Dublin Colleges of Physicians ... / [Anthony Todd Thomson].

  • Thomson, Anthony Todd, 1778-1849.
Date:
1830
Catalogue details

Licence: Public Domain Mark

Credit: Conspectus of the pharmacopoeias of the London, Edinburgh, and Dublin Colleges of Physicians ... / [Anthony Todd Thomson]. Source: Wellcome Collection.

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    water!/ fusion ; ;ind to decrepitate, if tliey spilt, lly, «ml crackle, when exposed lo a higli temperature. The salts most commonly adulterated arc subcarbonas potasaoi and jfubcarhuiunt s(Kta\ To try the first, make a solution of one part of the salt in eight of distilled water. If this become turbid after being neutralized with pure nitric acid, it indicates the presence of silej:; if a white precipitate be thrown down by muriate of barytes, or acetate of lead, sulpfiuric salts are indicated; and muriatic salts by a wliite precipitate being formed with nitrate of silver. If a white precipitate ixi produced by a solution of oxalate of potash, /tme, or its carbonatest is present. The same tests show the presence of simitar substances in subcarbonate of soda, if added to a saturated solution of it in acetous ^cid. The addition of tartaric acid discovers j)otash, by forming a precipitate of supertartrate of potash. The deliquescent and efflorescent salts should be kept and dispenstxi in stopped bottles; while those that are persistent will not suffer from being put up in paper. EARTHS, AND THEIR SALTS. The earths, like the alkalies, are probably compounds of oxygen with metallic bases. They are of very difficult fusibility ; very spa- ringly soluble; and unite with the acids, forming neutral salts. Those that are soluble in water possess properties .very similar to those of the alkalies; they are caustic; change to green vegetable blues and reds; and, combined with oils, form soap. Two earths, only, in their pure state, are used in medicine; lime and magnesia. The former, which is chiefly em]>loyc<I in pharma- ceutical operations, should be used as soon after it is burnt as possible; and each should be preserved in very closely-stopped bottles, as both attract, powerfully, the carbonic acid contained in atmospheric air. The solution of lime, or lime-water, should be kept in small bottles, perfectly full and well corked; for, by the contact of air, the lime attracts carbordc acid, loses its solubility and forms a pellicle of carbonate of lime on the surface of the water. The Neutral Earthy Salts do not require any particular care or management, except that they ought not to enter into extempo- laneous prescriptions with substance’s which are likely to decompose them; or with those acids with which they form insoluble compounds; as, for example, chalk with sulphuric acid. METALS, AND THEIR SALTS. Mktals5, which are supposed to be simple substances, have a greater specific gravity than any other chiss of bodies; arc dense, opaque, susceptible of a fine polish, tenacious; and are the best conductors of heat. They are more or less fusible, and may be volatilized by heat. In their mctalljc state they have affinities for each other, for oxygen,