An improvement in the method of constructing the retorts and furnaces employed in the manu facture of bisulphide of carbon has been effected by S. H. Johnson. The object is to facilitate the replacement of the broken or burnt retorts, without the necessity of pulling down the furnace work, thus preventing the loss of heat usually sustained. This is attained, firstly, by employing a hori zontal rotort for the vaporization of the sulphur, in conjunction with a vertical one fur heating the charcoal ; and secondly, by forming the flues for heating the vertical retort in an iron cylinder, open at both ends, with its axis in the line of the axis of the retort. Inside this cylinder and concentric with it, a cylindrical lining of firebrick is constructed, leaving a space between it and the cylinder, filled with a suitable non-conducting material. At the sides and end of the furnace, are passages for conducting the products of combustion into the upper retort-thamber. Below this chamber, and between the flues, the horizontal retort is set. As this latter is Dot required to be very highly heated, the products of combustion do not come into contact with it, except at the end. It is set in a material which will not burn very hard, such as a mixture of fire clay and ashes, so that when burnt out or broken, it may readily be drawu out from the front, without disturbing the brickwork of the furnace. Its mouth is closed by an iron cover. The retort chamber is constructed within a cylinder of iron plating; tbe lining, which is exposed to the fire, is built up of firebrick, and between it and the iron cylinder is a backing of sand or ashes. The upper or vertical retort is set in this chamber, and communicates with the horizontal retort at its lower end. A joint is made between the two seetions with fireclay, with which a little finely ground glass may be mixed, to make it burn more soundly. The vertical retort is supported near its upper end by a number of radial firebricks, made for the purpose. On the side next the chimney, these bricks are set with narrow spaces between them, the spaces gradnally increasing in size as the opposite side is approached. This is done with the object of rendering the draught uniform. The vertical retort is furnished with a cylindrical iron head, which communicates with an ordinary condenser ; the cover is made air-tight by means of a luting of whiting or other material. The sulphur ia melted iu a cast-iron pot, and is drawn off from tbe bottorn by a pipe leading into the horizontal retort. The pot la eet in amongst the filling material, and becomes aufficiently hot for the purpose intended.
In the conduct of operations, the vertical retort is first charged with large piecea of wood charcoal, of the ordinary quality, made red hot. The retort is heated to a full red-heat, and the melted sulphur is allowed to flow into the lower retort, which is kept free from charcoal ae much as poseible. The sulphur vapour passes up among the red-hot charcoal, and forms bisulphide of carbon, which passes in a gaseous form to the coolers, and ie there condensed. The cover is removed every few hours, the charcoal is poked down, and fresh red-hot charcoal is introduced. The lower cover ia removed only at long intervals, to permit the clearing away of the accumulated charcoal ashes. When either retort breaks or becomes worn out, the furnace le allowed te cool, the upper retort is lifted out, and entirely removed if necessary, and the lower one is drawn out at the front, ahould it be required. The new retorts are introduced in the same way, and, for the purpose of making the joint between them, the cover is removed ; thus, on taking out only a few bricks of the lining—which are ao placed as to come out readily—and aome of the backing, free access is given to the interior of the retort chamber. By these arrangements, the cost of the repairs is very materially reduced, and the loss of heat, and consequent couaumption of fuel in the manu facture, is conaiderably lessened.
Uses.—The uses to which bisulphide of carbon ie or may be applied are both numerous and important. The extreme degree of cold required to freeze it under ordinary conditions enables it to be used in thermometers for registesring very low temperatures; and this property may be utilized for the production of ice, by directing a rapid current of air upon the liquid, which will then solidify the water aa well as itself. The great actinism of its light has attracted the attention of photographers, and a special lamp has been inveuted for burning it in conjunction with deutoxide of nitrogen, to obtain a flame peculiarly applicable to photography. It is used fur making chloride of carbon CCI4, for purifying paraffin by Alcan's method, and for cleaning amorphous phosphorus. With perfectly pure hiaulphide of carbon, the perfumes of the most delicate flowers have been separated, and even the odours of plante eaten by a cow have been recog-nized by treating her milk with it. For silver plating, a small quantity placed in the bath increases the brilliancy of the
deposit. In the manufacture of yellow prussiate of potash, and of aulphocyanide of ammonium, it plays an important part. Its inflammable and txplosive qualitiea are taken advantage of in making Phcenician fire, and a solution of phosphorus in hisulphide of carbon ia employed for making matches, and for filling inflammatory rockets and shells. Its antiseptic properties admit of more than one useful application, Tiller has proved that, in an atmosphere containing a small quantity ef bisulphide, animal and vegetable matters are effectually preserved against decomposition. A few drops will suffice, and, as it volatilizes at ordinary temperatures, no heat is required. Things may also be preserved for a very considerable time in closed vessels; upon opening them, the smell of bisulphide is very evident, but it soon evaporatea. About 44 lb. of meat were perfectly preserved with 5 grms. of bisulphide for a period of four weeks, with the temperature never under 20° (68° F.), and often reaching 30°-33° (86° to 91° F.), and no unpleasant flavour WU to be discovered. As a destroyer of insects in grain, its efficacy is unrivalled ; not only does an ex ceedingly small quantity of it suffice to kill every living insect in the room where it is used, but it even destroys the germs of life contained in larm and eggs. In France, it has beeu used for years aa a remedy against the Phylloxera, an insect that causes much destruction to the vines. It has been found that direct application of the preparation to the plants, while effective against the iusects, causes the leaves to wither, though they remain on the branchea. An ingenious remedy for this drawback is based upon the fact that, in treating oils with protochloride of aulphur in small propor tions, they are transformed into a solid elastic condition resembling indiarubber, but transparent. If bisulphide of carbon be added at the same moment, it will be entrapped to the extent of 70 per cint., giving rise to a gelatinous substance having. the appearance and consistence of quince jelly. This solid mass is difficult of ignition; it may he heated to 100° (212° F.) without giving a sign of fusion, and even at 160° (320° F.) forms only a black mass not easily inflammable. Though we have no vines in thie country, we have other crape which are equally in need of some protection against the ravages of insects, and there is good reason to suppose that the potato disease and similar scourgea may be combated as effectually as the phylloxera. Perhaps the greatest present demand for bisulphide of carbon is on account of its solvent powers. It is used by varnish makers; a solution of wax in CS2 ia employed for making wax paper, and a solution of indiarubber is used for a coating to mape. As a solvent of indiarubber, also, it is extensively used iu the manufacture of vulcanized indiaruhber ; but Poincare has found the structural leeions occaaioned by the gradual action of the vapours of this compound on various animals so serious that, in his opinion, ita usc should be restricted to articles of real necessity. In extracting fat from bones, it is not much employed ; and when used for removing grease from wool, the latter is left in a harsh and brittle condition, and of yellowish hue, due to the action of heat and bisulphide on the sulphurized constituents of the wool. The wool is not damaged by the bisulphide when applied in the cold ; hut the residual bisulphide adhering to the wool must be cleaned off by a current of bot air, steam, or hot water, which is certain to do the wool more or less injury. These considerations, as well as the cost of the bisulphide, render it incapable of competing with benzine for this purpose. In the extraction of oils frorn seeds, however, it 113 very extensively used, especially on the Continent. Colza and linseed principally are the seeds acted upon. They are first crushed to express some of the oil, and then dried by beating, before being subjected to the bisulphide treatment. Analyses show the residues to contain only 2 per cent. of oil, and 7 per cent. of water, whilst the residues from the ordinary pressure process gave 9 per cent. of oil, and 15 per cent. of water. The oil is also much improved in quality, the residue is still valuable for feeding cattle ; and the workmen suffer no inconvenience. One works near Berlin, employing only six men, manufac tures daily some 5600 lb. of oil good enough for lubricating machinery, using daily 15,400 lb. of bisulphide of carbon, of which about 60 lb. arelost. This loss of biaulpbide, amounting to about 1 lb. for every 220 lb. of seed treated, ia partly due to volatilization, and partly to its action on the metallic vessels. Copper vessels are rendered useless in a few years, iron less rapidly.