The letters of Faraday and Schoenbein, 1836-1862 : with notes, comments and references to contemporary letters / edited by Georg W.A. Kahlbaum and Francis V. Darbishire.

Date:: 1899

Credit: The letters of Faraday and Schoenbein, 1836-1862 : with notes, comments and references to contemporary letters / edited by Georg W.A. Kahlbaum and Francis V. Darbishire. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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$in pure oil of \'itriol and introducing into the green solution pure peroxide of barium, when ozone mixed with common oxygen will make its appearance, as \'ou may easily perceive b}^ your nose and other tests. By means of the ozone so prepared, 1 have rapidly oxidized silver at the temperature of — C, and by inhaling it produced a capital catarrh. Regarding nitrification, the most important fact 1 ha\'e dis- covered is the generation of nitrite of ammonia out of water and nitrogen, i. e. atmospheric air, which is certainly a most wonderful and wholly unexpected thing. To state the fact in the most general manner, it may be said that the salt mentioned is alwa3's produced if water be evaporated in contact with atmospheric air. This ma}' be shown in a variet}' of ways. Let, for instance, a piece of clean linen drenched with distilled water dry in the open air, moisten it then with ]jure water, and you will find that the liquid wrung out of the linen and acidulated with dilute sulphuric acid (chemically pure) will strike a blue colour with starch-paste containing iodide of potassium, by the by, the most delicate test for the nitrites. It is therefore a matter of course that shirts, handkerchiefs, table-cloths, in fact all linen, etc., must contain appreciable quantities of nitrite of ammonia; and if the chemistr}^ of Eng- land be not entirely different from that of Switzerland, you will find the same thing at the Ro\'al Institution. The purest water, suffered to evaporate spontaneously in the open air, will after some time have taken up enough nitrite of ammonia (continually being formed at the evaporating surface) to produce the nitrite reaction. If you make use of water holding a little potash, or any other alkali, in solution, the same results will be obtained, i. e. the nitrite of that base will be formed (of course in small quantity). The most convenient way of per- forming the experiment is to moisten a bit of filtering-paper with a dilute sf)lution of chemically pure potash etc., and to suspend it for twenty-four hours in the open air. On examining$