ART. THE IV. THE IRON MANUFACTURE OF GREAT BRITAIN-THEORETICAL- V. ON THE MODE OF TESTING BUILDING MATERIALS, AND AN ACCOUNT OF THE MARBLE USED IN THE EXTENSION OF THE UNITED STATES CAPITOL.-By Professor JOSEPH HENRY. . 59 91 On the Formation of Brass by Galvanic Agency Improvements in Smelting, and in Apparatus to be used therein Sanderson's Process for Refining and Improving the Manufacture of Iron Cliff Mine Merryweather Mining Company JOURNAL OF SILVER AND LEAD MINING OPERATIONS. The Silver Mines of California 121 THE MINING MAGAZINE: DEVOTED TO Mines, Mining Operations, Metallurgy, &c., &c. VOL. VII.-JULY & AUG., 1856.-Nos. I. & II. ART I-PROCESSES FOR THE DISTILLATION AND PURIFICATION OF THE PRODUCTS OF COAL. By C. B. MANSFIELD. No. 3. [Continued from page 291, Vol. VI.] THERE are other substances which may be considered as impurities, viz., naphthaline, a solid hydrocarbon, which, when pure, boils at 212 degs., and is therefore found chiefly in the camphole, and in the first half of the dead oil. Paranaphthaline, a solid hydrocarbon, which boils at a temperature above 300 degrees, and is therefore chiefly in the last portions of the dead oil. Besides these, the most volatile of the spirituous substances, viz., alliole, since it has an ill smell, may be considered as an impurity, when present in such benzole, as is required to be pure, all these, viz., naphthaline, paranaphthaline, and alliole, are removed by a sufficient quantity of concentrated sulphuric acid, which forms. peculiar compounds with them, which it dissolves and carries with it to the bottom of the other hydro-carbonaceous spirituous substances, on which, with the exception of camphole, it acts much less powerfully. I proceed now to the application of these facts to the purification of the different oils and spirituous substances manufactured according to the first part of my invention. If a very volatile spirit be required, which is not required to be entirely free from a slightly disagreeable smell, I take any portion of the most volatile part of the naphtha, separated according to the principles which I have set down; but I prefer to take for this purpose such as may have been distilled over, before the temperature in the retort in the second or third distillation, or in the last distilling vessel, if a complex rectifying apparatus be used, has risen above 80 deg. This spirituous substance, which I call alliole, will not be absolutely pure, being mixed with a certain portion of the benzole, but will usually be found to be characterized by the peculiar smell of the pure alliole. I add to this alliole about onefourth its bulk of a cold moderately dilute acid, for which purpose I prefer hydrochloric acid of specific gravity 1.16, mixed with five times its bulk of water; but a much stronger hydro VOL. VII.-1 chloric acid may be used, or oil of vitriol mixed with nine times. its bulk of water. I do not state that these preparations are absolutely necessary, but they are convenient, the requisite condition being, that the acids be not concentrated nitric or sulphuric acid; since these acids, when concentrated, destroy the alliole in proportion to the quantity in which they are used. I agitate the alliole with the acid in a suitable vessel, which should be nearly closed, or so constructed as to prevent evaporization of the spirituous substance for a length of time, which will vary with the quantity of spirituous substance which is under treatment; all that is necessary being to keep the acid and spirituous substance in a state of intimate mixture for a sufficient time, to enable the acid to form salts with the ammonia and oily alkaloids, which accompany the crude alliole; I then allow the vessel to stand undisturbed, till the two fluids have separated; I then draw off the acid liquor, and wash the alliole by agitating it with about its bulk of clean water in the same manner as with the acids. The alliole, if then allowed to separate from the water and drawn off, is fit for use. But it is convenient sometimes to rectify it again, and to allow it to stand for some time, after careful separation from any water that may accompany it, upon fresh-burnt lime, which will remove any acid and water that may still adhere to it. The spirituous substance so obtained will be found to have a slightly alliacious odor, somewhat resembling that of bisulphuret of carbon, to be extremely volatile, and if placed in a retort and distilled, should begin to boil about 65 degs. or 70 degs.; and the greatest portion of its bulk should distil over before the temperature from the retort arrives at 80 degs., and the temperature should then rise very fast, and the retort should be dry at about 90 degs. or a little above. This spirituous substance will be found to be an excellent solvent of caoutchouc, gutta-percha, and many of the resins; it will mix with pyroxylic spirit in equal proportions, if the spirit be not too much diluted with water, and may be used when so mixed for dissolving shell-lac, or shell-lac and guttapercha, or caoutchouc mixed, though it will not dissolve lac in sufficiently large quantities when alone, or it may be mixed with a solution of lac in pyroxylic spirit in similar proportions. And the proportions in which it may be mixed with any sample of pyroxylic spirit may be readily ascertained, by putting a known quantity of the alliole into a graduated glass, and pouring it into the pyroxylic spirit, at the same time shaking the mixture until the whole of the alliole is dissolved, and a clear transparent mixture results, which shows no streaks of milkiness when the surface in an open glass is slightly blown upon. The proportion or quantity of spirit which has been added to the alliole which was in the glass, shows the proportions in which they may be mixed. Alliole so prepared also yields a brilliant light when burned by the aid of a current of air. Next of the purification of benzole prepared from coal tar or the products of coal tar. If this be not required perfectly free from the odor of alliole, and if moderate purity be only required, I treat this spirit in the same manner which I have described for the treatment of alliole; and if it be required for burning with the aid of a current of air, as hereinafter described, I prefer to treat it in this manner, by which all the spirituous substance is preserved intact, while the picoline and other basic or alkaline substances, which chiefly cause the disagreeable smell of the naphtha, are removed; and I consider it sufficiently pure for this purpose when a piece of white deal, dipped first into the benzole and then into hydrochloric acid, does not acquire a red or pink color. If, however, a volatile substance be required as a solvent, or for any other purpose where freedom from an unpleasant odor is necessary, the treatment is different. Instead of agitating the benzole with dilute acid, I agitate it with concentrated sulphuric acid, in the proportion of about one half pound of acid to a gallon of the benzole, which destroys the alliole, at the same time that it removes the basic oils, and oxidizes any of the brown forming substance which may be present; and I prefer to add with the sulphuric acid a small portion of the nitrate of potash, or nitrate of soda, about one ounce to half a pound of sulphuric acid, or nitric acid, or nitrous acid, or aquafortis of specific gravity about 1.30, in the proportion of one fluid ounce to half a pound of sulphuric acid; the addition of nitric acid tends greatly to bring out the pleasant smell of the benzole from the more perfect oxidation of oxidable substances which are present, and from the formation of a small quantity of the sweet-smelling compound, of which I have already spoken, which, when the benzole is rectified, is separated in the residue; or instead of sulphuric acid, mixed with nitric acid or its salts, I use nitric acid, nitrous acid, or aquafortis alone, of specific gravity about 1.30 or 1.40, or nitric acid mixed with hydrochloric acid, or nitro-muriatic acid, in the proportion of half a pound of the acid to a gallon of the benzole, or instead of the nitrate of potash or soda, I use a similar proportion of bichromate of potash. I then, after agitation, allow the mixture to settle, and then draw off the benzole from the thickened acid. I then sometimes add to the benzole a small quantity of the chloride of lime and some moderately strong acid, and stir the mixture, but this further deoxidizing process is seldom necessary. And whether this last process be used or not, I now agitate the benzole with water and complete its purification in the same manner as the alliole is purified. The spirituous substance so obtained will be found to be very volatile; if placed in a retort, it should commence to boil at 30 degs., and the largest portion of it should come over before the temperature in the retort reaches 85 degs., and the retort should be dry at 100 degs, without leaving any residue. If subjected to a temperature of 20 deg. below 0 degs. (--20 degs.) it should de |