The annexed specification describes the improvements ot J. B. Moinier and Pierre Hip-polyte Boutigny, of Paris, for the preparation of fatty oils and tallows for candles, the patent for which was granted on the 8th of last month (Feb.) and the claim published on page 182, this volume, Scientific American. The improvements are adapted to the treating of all animal and vegetable fatty matters—such as tallow, lard, palm oil, &c, The improvement applies especially to the treatment of fatty matters in combination with alkalies by passing a strong current of sulphurous acid gas through the said combination. The effect of the use of sulphurous acid gas, and subjecting the mixture of fatty materials with alkalies to its action is to free the compound from impurities, and harden it, so that candles will be produced therefrom, equal to wax or sperm, and giving as brilliant a light. Sometimes, instead of mere sulphurous acid gas being employed, it may be used in combination with the bases—a sulphite— containing calculated quantities of sulphurous acid. The use of the gas requires no alteration in the mechanical processes of preparing fatty acids with alkalies; the mixture of any fatty acid, and an alkali is simply treated with sulphurous acid gas by being exposed to its action for two successive hours. After this the residue or product is cleared of the gas by being washed by injecting high pressure steam among it. This is the whole invention or discovery ; the matter is treated with steam until it is perfectly free from the gas. To render tallow, grease, or lard of a very superior quality, they have simply to be melted, then exposed to a current of the sulphurous acid gas for two hours ; then steamed as above described, when the said matters will be found to be greatly improved. A patent was granted for the discovery in France, on the 196h May, 1852, and it has been deemed of no small importance and value, or the inventors wouldnot have patented it here. The above described invention is not an identical transcript of the specification filed, in our Patent Office ; we have rendered the description more plain and full we believe, than the said document. The claim of the patent will be found by our readers on the page referred to. Kaow-ing how great the lard, tallow, and sperm interests are in our country, and knowing the importance and value to our people of any improvements in the making of candles, we are persuaded that the above information will be of great interest to a large number of our readers. We would state here, however, in respect to this patent, that there does not appear to be anything new in it, but the employment of sulphurous acid gas instead of sulphuric acid. It is an old and well known plan to purify tallow to produce stearic acid for beautiful candles by decomposing lime soap with sulphuric acid, and the employment of steam to produce decomposition. The way to do this has been to melt tallow in troughs containing water, by steam heat, then introduce milk of lime—an alkaline base—which is kept agitated for a few hours, when the whole is converted into a lime soap. This lime soap without water is treated in a second trough with sulphuric acid, sided by the heat of steam, by which process the sulphuric acid and lime, combine and form the sulphate of lime, which is precipitated to the bottom and a clear transparent layer ot fat oil is found on the surface, which, on being transferred to moulds, solidifies into blocks. These blocks contain a mixture of oleic and stearic acids, which are separated from one another by mechanical pressure. We repeat again, that there appears to be nothing new in the specification obtained from our Patent Office, excepting the use of sulphurous acid gas, as a substitute for sulphuric acid. A company of Englishmen are now working successfully a copper mine in Cherokee Co., N. C. The copper ore is said to be strongly impregnated with silver. The Ash-ville News states that a substance very much resembling, and believed by many to be the real diamond, has been recently found in Buncombe Co. It cuts glass and steel. The finder has several pieces of large size.
This article was originally published with the title "Candles Equal to Wax or Sperm, Made from Tallow and Lard" in Scientific American 8, 27, 216 (March 1853)