Page:Experimental researches in chemistry and.djvu/240

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1827.]
On Labarraque's Disinfecting Soda Liquid.
225

by Mr. Phillips[1] led me to expect. The solution had but little odour of chlorine; its taste was at first sharp, saline, scarcely at all alkaline, but with a persisting astringent biting effect upon the tongue. When applied to turmeric paper, it first reddened and then bleached it.

9. A portion of the solution (2) being boiled, gave out no chlorine; it seemed but little changed by the operation, having the same peculiar taste, and nearly the same bleaching power as before. This is a sufficient proof that the chlorine, though in a state ready to bleach or disinfect, must not be considered as in the ordinary state of solution, either in water or a saline fluid; for ebullition will freely carry off the chlorine under the latter circumstances.

10. A portion evaporated on the sand-bath rather hastily, gave a dry saline mass, quite unlike that left by the saturated solution already described (6); and which, when dissolved, had the same astringent taste as before, and bleached solution of indigo very powerfully: when compared with an equal portion of the unevaporated solution which had been placed in the mean time in the dark, it bleaching power upon diluted sulphate of indigo was 30, that of the former being 76. Another portion evaporated in a still more careful manner, gave a mass of damp crystal, which, when dissolved, had the taste, smell, and bleaching power of the original solution, with almost equal strength.

11. These experiments showed sufficiently that the whole of the chlorine had not acted upon the carbonate of soda to produce chloride of sodium and chlorate of soda; that much was in a peculiar state of solution or union which enabled it to withstand ebullition, and yet to act freely as a bleaching or disinfecting agent; and that probably little or none had combined with the sodium, or been converted into chloric acid. To put these ideas to the test, two equal portions of the Labarraque solution were taken; one was placed in a large tube closed at one extremity, diluted sulphuric acid was added till in excess, and then air blown through the mixture by a long small open tube, proceeding from the mouth, for the purpose of carrying off the chlorine; the contents of the tube

  1. Phil. Mag. N. S. i. 376.