Agricultural chemistry / [George Cox].

  • Cox, George
Date:
1844
Catalogue details

Licence: Public Domain Mark

Credit: Agricultural chemistry / [George Cox]. Source: Wellcome Collection.

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    The inorganic or mineral constituents will be treated of in the following order:— POTASH AND ITS SALTS. That which is generally known among farmers and the commercial world under the name of potash, is an impure article, brought to this country in immense quantities from Russia and America. It is obtained by burning land plants, lixivating, or washing their ashes, and evaporating the solution to dryness. The ingredients not taken up are for the most part composed of silica and insoluble salts. The article as thus prepared, is a carbonate of potash, and contains sulphate, muriate, and silicate of potash, be- sides at times numerous other impurities, in consider- able quantities. The potash of chemists is a very different article, and possesses very active properties, being alkaline in the highest degree. The bodies to which the term alkaline is attached, possess peculiar pro- perties. They change the blue juices of vegetables to a green (with the exception of litmus), and the yellow tints they transform to a brown. They possess a very acrid taste, and have the property of ren- dering oils miscible with water. The alkalies are four in number, viz., potash, soda, lithia, and ammonia. The first three are called fixed alkalies, because it requires the most intense de- gree of heat to volatilize them ; the last is called vo- latile alkali, because at the natural temperature it ex- ists in the gaseous state. There are four other bodies
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