Brunswick Advertiser Vol.6, No. 18 November 6, 1880 Wilmington Review, October 22nd. Dr. Thos. F. Wood, of this city, sometime since collated a number of facts relative to the production of turpentine, and its manufactured results, such as spirits, rosin and oil, in response to some enquiries submitted to him by Prof. Fluckiger, for insertion in the Pharmacographia. Dr. Wood’s article has been furnished to New Remedies a monthly medical trade journal published in New York city, in the October number in which it appears. it contains matter which will interest all of our readers, and we reproduce it here. In reading the article, it must be understood that it is a compilation of replies to interrogatories, the latter being omitted: Of the turpentine collected in this district, very little is shipped north. Most all of it is distilled upon the water courses near the pine forests. The small quantities of crude turpentine now sent north are used in making printers’ ink. Turpentine is distilled in copper stills now. Formerly iron stills were used. Then the resulting oil was red. When the first copper still was used in Wilmington, the clear, uncolored oil shipped north was rejected, because it was not considered genuine “spirits.” All crude turpentine is distilled with water. The part which water plays in the process will be seen hereafter. The present distinctions as to the grades of rosin are somewhat different from yellow and transparent. It is not the presence of water which makes rosin yellow. If water gets into rosin, which it does sometimes by accident, the rosin becomes opaque. All the better grades of rosin are yellow or amber color, more correctly; but the term “yellow rosin” is not used here commercially or otherwise. The grade of the rosin depends, first upon the quality of the turpentine, and, second, upon the skill in distilling. “Virgin turpentine,” the first exulation from a newly clipped tree, if skilfully distilled, will yield “window-glass rosin,” of which there are two or three grades. If, by any means, water gets into prime rosin, it becomes opaque. This accidental addition of water must take place after the rosin has been drawn off from the still. “Yellow dip” turpentine, which is the running of the second and subsequent years, yields the medium grades of rosin, while the “scrapings,” the inspissated gum from the tree facings, yields an inferior rosin, from very dark to almost black. The black rosin is not due to burning in the still, as has been stated. Anhydrous rosin is the greater part of the stock produced; the opaque rosins, being accidental, are limited. The following description of the process of distillation may explain further: A fifteen barrel copper still (barrel weighing 220 pounds each) is charged early in the morning.—Heat is applied until the mass attains a uniform temperature of from 212 to 316 degrees F. This is continued until the accidental water that is, the water contained in the crude turpentine as it comes from the forest, has been driven off. The first product distilled over is pyroligneous acid, formic acid, ether and methylic alcohol, with water. This is known as low wine. All the accidental water having been distilled off, a small stream of cold water is now let in so that the heat is kept at or below 316 degrees F., the boiling point of oil of turpentine. The oil of turpentine and water now come over, and the mixture is caught in a wooden tub. The distillate is caught from the still, and separates into water and oil. There is an overflow spout, which discharges into a tub. The water is kept low enough in the lower part of the tub to prevent its overflowing through the cock into the receptacle. From this receptacle it is put into oak casks, well made with iron hoops, and securely glued inside. The distillers test the quality of the flow from time to time in a proof glass. The distillation is continued until the proportion of fluid coming over is nine of water to one of oil of turpentine. At this stage the heat is withdrawn, the still-cap is taken off, and the hot rosin which remains in a fluid state in the still, is drawn off by a valvular cock at the side of the still near the bottom. This rosin passes through a strainer, before it reaches the vat, to rid it of foreign substances, such as straw, pine cones, chips, etc.—From the vat it is bailed by wooden buckets, fixed on a long handle, into the barrels. Rosin is graded by standard samples fixed upon by the “Produce Exchange.” The yield of oil of turpentine from “virgin drip” is about six gallons to barrel. The yield of oil of turpentine from “yellow dip” is about four gallons to barrel. The yield of oil of turpentine from “scrapings” is about two gallons to barrel. Other products now attract our attention, viz: the distillation of rosin oil. The rosin oil of commerce is produced in the following way: Rosin is introduced into an iron still, the lower grades being used for this purpose, and heat is applied until the temperature reaches from 316 to 320 degrees F. Water and pyroligeneous and naptha. The heat is then raised to near the red heat of iron, when the rosin boils, and water and oil of rosin distil over together. This is crude rosin-oil. It is heavy, nearly opaque, whitish viscid fluid, opalescent on the surface. This crude rosin oil is rectified by distillation, and the resulting oil is transparent, with a decidedly bluish cast by reflected light. It is deeply opalescent, more so than petroleum oil. The residuum left in the still is a black mass with a shining fracture, giving the hues of crystal analine. Other products still remain to be spoken of, viz: naptha and oil of tar. Tar, when distilled, yields pyroligneous acid, water, naptha or spirits of tar. The naptha, when purified by a second distillation, is clear and of a very pleasant terebinthinate odor. The oil of tar comes over in the latter part of the process and a black residuum remains in the still resembling pitch. All but the last named of these articles have a commercial value. Tar is distilled in iron retorts, just as rosin is. There are many complex bodies which have come to the attention of the manufacturers during their operations. Some of them have been very intelligently worked out and identified by Mr. William A. Martin, the chemist of the works we have visited.- - Some remain to be investigated.-- Terebinthine products have always been exceedingly interesting chemically, and just now we are moving towards practical commercial results. I am expecting to announce, at no distant day, that we have made a sure step in the right direction.
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