CHEMICAL SCIENCE. 209 



than either, when used separately. The product is cheaper, and will 

 also admit of the use of platted wicks ; and the tendency of the stearic 

 acid to crystallize is corrected by the employment of the stearine of the 

 cocoa-nut.. These candles are known by the name of "composite," 

 and have been sold in immense quantities. 



Mr. Carpmael next called attention to the modern introduction of 

 palm-oil in the manufacture of candles, the properties of which are 

 peculiarly suited to candle-making. The stearine of it, even in its crude 

 state, makes excellent " dip " candles, when the quality of the light only 

 is considered ; but they are of a bad color. The palm stearine also 

 makes good lamp candles : but the great use of palm-oil as a caudle 

 stuff is when distilled for this purpose. The crude oil is first treated 

 with acid to bring it into an acid state, and the same is then distilled 

 by means of steam, which, in its passage from the boiler, passes 

 through a series of pipes heated by a furnace, by which the steam be- 

 comes very highly heated, (600 Fahr.,) and in that state it enters into 

 the still, and amongst and below the chemically prepared palm-oil, 

 which is thereby caused to distil over, and is condensed in suitable 

 apparatus ; the product is pressed ; and by these means a most beau- 

 tiful material, closely resembling spermaceti, is obtained, and from 

 which those modern manufactures of candles, now so largely and so 

 well known as Belmont sperm and Belmont wax, are produced. 



LIGHT FOR ILLUMINATION OBTAINED FROM THE BURNING OF HYDROGEN. 



M. GILLARD, of Paris, claims the production of a useful light and 

 great heat from the combustion of hydrogen in contact with a coil of 

 platinum wire the hydrogen being produced by the decomposition 

 of water. The apparatus employed is very simple, and consists essen- 

 tially of one or more cylinders of iron arranged horizontally in a fur- 

 nace, similar in all respects to the usual arrangement for the produc- 

 tion of coal gas. The retorts are charged with wood-charcoal reduced 

 to small fragments, of uniform size, and heated to an intense degree. 

 Through each of the retorts steam is conducted in a tube pierced with 

 numerous very minute holes, so disposed, as to distribute the steam in 

 a uniform and very gradual manner over the heated coal. The boiler 

 for the production of the steam is conveniently situated in the same 

 furnace employed for heating the retorts. Decomposition of water 

 ensues of course, accompanied with the production of carbonic acid 

 (CO 2 ), carbonic oxide (CO) in small quantity, of free hydrogen and a 

 limited quantity of light carburetted hydrogen gas, (C 2 H.) The mix- 

 ture of these gases is conducted through a lime purifier to remove 

 carbonic acid, and, without farther washing or purification, the product 

 is ready for use. Consisting almost wholly of hydrogen gas, the flame 

 of its combustion is of course very feebly luminous ; to obviate this 

 difficulty, it is burned in contact with a cage or net-work of platinum 

 wire gauze surrounding an ordinary argand burner, protected by a 

 glass chimney. This simple contrivance is perfectly successful, and 

 the light given out from gas lamps of this construction is extremely 

 vivid and constant. 



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