The elements of experimental chemistry (Volume 2).

  • Henry, William, 1774-1836.
Date:
1819
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Licence: Public Domain Mark

Credit: The elements of experimental chemistry (Volume 2). Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    with clay, except within about half an inch of the sealed end. Put first into it a drachm or two of phosphorus, cut into small pieces, and then fill the tube with small bits of fresh burnt lime, of the size of split peas. Stop the mouth of the tube loosely with a little pa- per, in order to prevent the free access of air.—Next, heat to red- ness that part of the tube which is coated with clay, by means of a chafingdish of red-hot charcoal; and, when the lime may be sup- posed to be ignited, apply heat to the part containing the phospho- rus, so as to sublime it, and to bring the vapour of it into contact with the heated lime. The lime and phosphorus will unite, and will afford a compound of a'reddish-brown colour.—Phosphuret of barytes and of strontites may be prepared in a similar manner. If the carbonate of lime be substituted for pure lime, the carbonic acid is decomposed. Its carbon is set at liberty, and appears in the state of charcoal; while its oxygen unites with the phosphorus; and the phosphoric acid, thus produced, forms phosphate of lime. In this process, discovered by the late Mr. Tennant, carbonic acid is decomposed by the conspiring affinities of phosphorus for oxygen, and of lime for phosphoric acid, though the former affinity only would be inadequate to produce the effect. The phosphuret of lime has the remarkable property of decom- posing water at the common temperature of the atmosphere; and the water afterwards contains phosphite, or hypo-phosphite, not phosphate, of lime.* Drop a small piece of it into a wine-glass of water, and in a short time bubbles of phosphuretted hydrogen gas will be produced; which, rising to the surface, will take fire, and explode. If the phosphuret of lime be not perfectly fresh, it may be proper to warm the water to which it is added. Into an ale-glass put one part of phosphuret of lime, in pieces about the size of a pea (not in powder), and add to it half a part of chlorate of potash. Fill the glass with water, and put into it a fun- nel, with a long pipe, or narrow glass tube, reaching to the bottom. Through this pour three or four parts of strong sulphuric acid, which will decompose the chlorate; and, the phosphuret also decomposing the water at the same time, Hashes a fire dart from the surface ot the fluid, and tM bottom of the vessel is illuminated by a beautiful green light. (Davy.) Another combination of phosphorus, the properties of which ren- der it a fit subject of amusing experiments, is the phosphuretted hydrogen gas. Art. 3.—Phosphuretted Hydrogen Gas. By heating solid phosphorous acid out of the contact of air, a large quantity of elastic fluid is generated, which may be collected by a proper apparatus, and has singular properties. It has a disagreeable smell, but is not so offensive as bi-phosphu- retted hydrogen. It does not explode spontaneously, but detonates ' Gay Lnssac, 85 Ann. da Cliim. 206, and Ann. dc Chim. etPhys. vi. JR.