SULPHURIC ACID

Vitriolic Acid , or Oil of Vitriol ( Acid sulfur i que , Fr.; Schwefelsaüre , Germ.). This important product, the agent of many chemical operations, was formerly procured by the distillation of dried sulphate of iron, called green vitriol, whence the corrosive liquid which came over, having an oily consistence, was denominated oil of vitriol. This method has been superseded in Great Britain, France, and most other countries, by the combustion of sulphur along with nitre, in large leaden chambers; but as the former proce , which is still practised at Bleyl in Bohemia, and Nordhausen in Saxony, gives birth to some interesting results, I shall describe it briefly. Into a long horizontal furnace, or gallery of brickwork, a series of earthenware retorts, of a pear shape, is arranged, with curved necks fitted into stoneware bottles or condensers. Each retort is charged with sulphate of iron, which has been previously heated to moderate redne . The first product of the distillation, a slightly acidulous phlegm, is allowed to escape; then the retort and receiver are securely luted together. The fire is now raised, and urged briskly for 36 hours, whereby the strong sulphuric acid is expelled, in the form of heavy white vapours, which condense in the cold receiver into an oily-looking liquid. The latter portions, when received in a separate refrigerator, frequently concrete into a crystalline ma , formerly called glacial oil of vitriol. About 64 pounds of strong acid may be obtained from 600 pounds of copperas. It is brown-coloured; and varies in specific-gravity from 1·842 to 1·896. Its boiling point is so low as 120° Fahr. When re-distilled in a gla retort, into a receiver surrounded with ice, a very moderate heat sends over white fumes, which condense into a soft solid, in silky filaments, like asbestos, tough, and difficult to cut. When this is exposed to the air, it emits copious fumes of sulphuric (not sulphurous) acid. It burns holes in paper as rapidly as a red-hot iron. Dropped in small quantities into water, it excites a hi ing noise, like ignited metal; and in larger quantities, it occasions an explosion. By dropping a fragment of it into a poised phial containing water, and stoppering instantly, to prevent the ejection of liquid, by the ebullition which always ensues, I got a dilute acid, containing a known portion of the solid acid, from the specific gravity of which, as well as from its saturating power, I ascertained that the above solid sulphuric acid was truly anhydrous ( void of water ), consisting of 1 equivalent proportion of sulphur, and 3 of oxygen; or, by weight, of 16 of the former, and 24 of the latter. This acid makes a red solution of indigo. The production of sulphuric acid from sulphur and nitre may be elegantly illustrated by means of a gla globe with a stoppered hole at its side, and four bent gla tubes inserted into a leaden cap in its upper orifice. The first tube is to be connected with a heated matra , disengaging sulphurous acid from copper filings and sulphuric acid; the second with a retort, disengaging more slowly deutoxide of azote (nitric oxide) from copper filings and nitric acid; the third with a ve el for furnishing steam in a moderate current towards the end of the proce , when no water has been previously admitted into the balloon; the fourth tube may be upright, and terminate in a small funnel. Through the opening in the side of the globe, atmospherical air is to be admitted from time to time, by removing the stopper; after which, the residuary lighter azote may be allowed to escape by the funnel orifice. The nitric oxide first absorbs oxygen from the air, becomes, in consequence, nitrous acid vapour, which giving up one third of its oxygen to the sulphurous acid, converts this, with the aid of water, into sulphuric acid, while itself returning to the state of nitric oxide, is again qualified to take oxygen from the air, and to transfer it to the sulphurous acid gas; and thus in perpetual rotation. These oxygenating and dis oxygenating proce es continue until nearly the whole oxygen of the atmospheric air contained in the globe is consumed. Were there little aqueous vapour present, those gases would soon cease to operate upon each other; for though the nitric oxide became nitrous acid, this would oxygenate little of the sulphurous acid, because the three substances would condense into white crystals upon the sides of the balloon, like hoar frost upon a window-pane in winter. These indicate a deficiency of aqueous vapour, and an exce of nitrous acid. On the admi ion of steam, the crystals disappear, the sulphuric acid is liquefied, the nitrous acid is converted into nitric acid and nitric oxide; the former of which combines with the water, while the latter is converted by the atmospheric oxygen into nitrous acid vapour. A certain quantity of water is therefore requisite to prevent the formation of that crystalline compound, which condenses the nitrous acid, and renders it inoperative in transforming fresh portions of sulphurous acid into sulphuric. On these principles alone is it po ible to oxygenate the sulphurous acid, by the nitrous acid resuming and surrendering a dose of oxygen, in perpetual alternation. It was MM. Clement and Desormes who first had the sagacity to trace these complicated changes. They showed that nitrous acid gas and sulphurous acid gas mixed, react on each other through the intervention of moisture; that there resulted thence a combination of sulphuric acid, deutoxide of azote (nitrous gas), and water; that this crystalline compound was instantly destroyed by more water, with the separation of the sulphuric acid in a liquid state, and the disengagement of nitrous gas; that this gas re-constituted nitrous acid at the expense of the atmospheric oxygen of the leaden chamber, and thus brought matters to their primary condition. From this point, starting again, the particles of sulphur in the sulphurous acid, through the agency of water, became fully oxygenated by the nitrous acid, and fell down in heavy drops of sulphuric acid, while the nitrous gas derived from the nitrous acid, had again recourse to the air for its lost dose of oxygen. This beautiful interchange of the oxygenous principle was found to go on, in their experiments, till either the sulphurous acid, or oxygen in the air, was exhausted. They verified this proposition, with regard to what occurs in sulphuric acid chambers, by mixing in a crystal globe the three substances, deutoxide of azote, sulphurous acid, and atmospheric air. The immediate production of red vapours indicated the transformation of the deutoxide into nitrous acid gas; and now the introduction of a very little water caused the proper reaction , for opaque vapours rose, which deposited white star-form crystals on the surface of the gla . The gases were once more transparent and colourle ; but another addition of water melted these crystals with effervescence, when ruddy vapours appeared. In this manner the phenomena were made to alternate, till the oxygen of the included air was expended, or all the sulphurous acid was converted into sulphuric. The residuary gases were found to be nitrous acid gas, and azote, without sulphurous acid gas; while unctuous sulphuric acid bedewed the inner surface of the globe. Hence, they justly concluded their new theory of the manufacture of oil of vitriol to be demonstrated. In consequence of their discovery, the manufacture of this acid has received such improvements, that a nearly double product of it may now be obtained from the same weight of materials. Indeed, the economy may be reckoned to be much greater; for one half of the more costly ingredient, the nitre, formerly employed with a given weight of sulphur, suffices at present. In the manufacture of sulphuric acid upon the great scale, two different systems of working were long prevalent; the intermittent or periodical, and the continuous or uniform. Both were carried on in large leaden chambers. In the former, the chambers were closed during the period of combustion and gaseous combination, but were opened from time to time to introduce fresh atmospheric air. This method is, I believe, generally abandoned now, on account of the difficulties and delays attending it, though it afforded large products in skilful hands. In the latter, a continuous current of air is allowed to enter at the oven in front of the chamber for the combustion of the sulphur, and there is a constant escape of nitrogen gas, with a little sulphurous acid gas, at the remote end of the roof. IMG:4147767755307473660_illo1220.png:Sulphuric acid chamber Fig. 1101. represents a sulphuric acid chamber, a , a , are the brick or stone pillars upon which it rests; b , b , are the sustaining wooden beams or joists; c , is the chimney for the discharge of the nitrogen; d , is the roof, and e , the sole of the hearth for the combustion of the sulphur; f , is the cylindrical tunnel, or pipe of lead or cast iron, for conducting the gasiform materials into the chamber; g , is the steam-boiler; and h , the steam-pipe. That plan is variously modified, by different oil-of-vitriol makers in this country and in France. Very frequently, the oven e , d , is not situated under the chamber, but is built at the end of it, as at i , and arched over with brick, the crown being 9 inches thick. The pipe f , 18 inches in diameter, is then placed outside of the chamber, being inserted into a brick chimney, and, turning rectangularly, enters it opposite k . The sole of the hearth e , is a thick plate of cast iron (not hollowed as shown in the figure), 5 or 6 feet long, and 3 or 4 broad, with a small fireplace constructed beneath it, whose smoke-flue runs outwards, under the floor, to the side wall of the building. The oven is in this case about 2 feet in height, from the sole to the roof; and it has an iron door, about 12 inches by 15, which slides up and down in a tightly-fitted iron frame. This door is frequently placed in the side of the oven, parallel to the long side of the leaden chamber. A stout collar of lead is bolted to the chamber, where the pipe enters it. At the middle of the side of the chamber, about 2 feet above the ground, a leaden trough is fixed, which serves as a syphon-funnel and water-trap for introducing water to the acid gases. Several manufacturers divide the chamber into a series of rectangular compartments, by parallel leaden screens, 10 or 12 feet asunder, and allow these compartments to communicate by a narrow opening, or a hole 1 foot square, in the top and bottom of each screen alternately. Thus the fumes, which enter from the chimney-pipe over k , will be forced, by the screen at b , to descend to 1, and pa through the opening there, to get into the second compartment, whence they will escape near the top at 2, thus circulating up and down, so as to occasion a complete agitation and intermixture of their heterogeneous particles. Into the side of the chamber, opposite to the centre of each compartment, a lead pipe enters, and proceeds towards the middle of the area, terminating in a narrow orifice, for discharging a jet of high-pre ure steam from a boiler loaded with 40 pounds upon the square inch. This boiler should be placed under a shed exterior to the building. It deserves to be noted, that the ince ant tremors produced in this pipe by the escape of the steam, cause the orifice to contract, and eventually to close almost entirely, just as the point of a gla tube does when exposed directly to the flame of a blowpipe. Provision should therefore be made against this event, by the chemical engineer. Equidistant between the middle point and each end of the chamber, two round holes are cut out in its side, about 16 inches in diameter, and 2 feet from the floor; the sheet lead being folded back over the face of the strong deals which strengthen the chamber in that place. The edges of the holes are bevelled outwards, so as to fit a large conical plug of wood faced with lead, called a man-hole door. One or other of these doors is opened from time to time, to allow the superintendent to inspect the proce , or workmen to enter, after the chamber is well ventilated, for the purpose of making repairs. The joists or tie-beams, that bind the rafters of the roof of both the leaden chamber and the house, must be at least 7 inches deep, by 3 broad, and of such length as to have their ends supported upon the outer wall, or the columnar supports of the roof, in case a number of chambers are enclosed together in parallel ranges under a vast shed. These beams, which lie two feet apart, suspend the leaden roof, by means of leaden straps, soldered to its upper surface and edges. The sides of the chamber are sustained by means of similar leaden straps affixed to the wooden posts (uprights), 4 inches broad by 3 thick, placed two or three feet apart along the sides of the chamber; resting on the ground below, and mortised into the tie-beams above. Some chambers rest upon a sand-floor; but they are preferably placed upon wooden joists, supported by pillars stretching over an open area, as shown in the figure, into which the workmen may descend readily, to examine the bottom. The outlet c , on the top of the chamber, is sometimes joined to a long pipe of lead laid nearly horizontally, with a slight inclination upwards, along the roof, for favouring the condensation and return of acid matter. At the extremity l , of the chamber, which, having a downward slope of 1 inch in every 20 feet, should stand from 3 to 6 inches (according to its length) lower than i , one leg of an inverted syphon pipe is fixed by fusion, into which the liquid of the chamber pa ing, will show by its altitude the depth on the bottom within. From the cup-shaped orifice of that bent-up pipe, the acid of the chamber is drawn off by an ordinary leaden syphon into the concentration pans. The sheet lead of which the sides and top are made, should weigh from 5 to 6 pounds per square foot; that of the bottom should be nearly of double thickne . Having now detailed, with sufficient minutene , the construction of the chamber, I shall next describe the mode of operating with it. There are at least two plans at present in use for burning the sulphur continuously in the oven. In the one, the sulphur is laid on the hearth e , (or rather on the flat hearth in the separate oven, above described,) and is kindled by a slight fire placed under it; which fire, however, is allowed to go out after the first day, because the oven becomes by that time sufficiently heated by the sulphur flames to carry on the subsequent combustion. Upon the hearth, an iron tripod is set, supporting, a few inches above it, a hemispherical cast-iron bowl (basin) charged with nitre and its decomposing proportion of strong sulphuric acid. In the other plan, 12 parts of bruised sulphur, and 1 of nitre, are mixed in a leaden trough on the floor with 1 of strong sulphuric acid, and the mixture is shovelled through the sliding iron door upon the hot hearth. The succe ive charges of sulphur are proportioned, of course, to the size of the chamber. In one of the largest, which is 120 feet long, 20 broad, and 16 high, 12 cwt. are burned in the course of 24 hours, divided into 6 charges, every fourth hour, of 2 cwt. each. In chambers of one-sixth greater capacity, containing 1400 metres cube, 1 ton of sulphur is burned in 24 hours. This immense production was first introduced at Chaunay and Dieuze, under the management of M. Clement-Desormes. The bottom of the chamber should be covered at first with a thin stratum of sulphuric acid, of spec. grav. 1·07, which decomposes nitrous acid into oxygen and nitrous gas; but not with mere water, which would absorb the nitrous acid vapours, and withdraw them from their aerial sphere of action. The vapour of nitric acid, disengaged from the nitre on the hearth of the oven, when brought into intimate contact with the sulphurous acid, either gives up oxygen to it, becomes itself nitrous gas, and converts it into sulphuric acid; or combines with the sulphurous acid into the crystalline compound above described, which, the moment it meets with moisture, is decomposed into sulphuric acid and nitrous gas. The atmospherical oxygen of the chamber immediately reconverts this gas into nitrous or nitric acid fumes, which are again ready, with the co-operation of sulphurous acid gas and aqueous vapour, to produce fresh quantities of hydrous sulphuric acid (oil of vitriol) and nitrous gas. At low temperatures, this curious play of chemical affinities has a great tendency to form the crystalline compound, and to deposit it in a crust of considerable thickne (from one-half to one inch) on the sides of the chamber, so as to render the proce inoperative. A circumstance of this kind occurred, in a very striking manner, during winter, in a manufacture of oil of vitriol in Ru ia; and it has sometimes occurred, to a moderate extent, in Scotland. It is called, at Marseilles, the maladie des chambres . It may be certainly prevented, by maintaining the interior of the chamber, by a jet of steam, at a temperature of 100° F. When these crystals fall into the dilute acid at the bottom, they are decomposed with a violent effervescence, and a hi ing gurgling noise, somewhat like that of a tun of beer in brisk fermentation. M. Clement-Desormes demonstrated the proposition relative to the influence of temperature by a decisive experiment. He took a gla globe, furnished with three tubulures, and put a bit of ice into it. Through the first opening he then introduced sulphurous acid gas; through the second, oxygen; and through the third, nitrous gas (deutoxide of azote). While the globe was kept cool, by being plunged in iced water, no sulphuric acid was formed, though all the ingredients e ential to its production were present. But on exposing the globe to a temperature of 100° Fahr., the four bodies began immediately to react on each other, and oil of vitriol was condensed in visible str iæ . The introduction of steam is a modern invention, which has vastly facilitated and increased the production of oil of vitriol. It serves, by powerful agitation, not only to mix the different gaseous molecules intimately together, but to impel them against each other, and thus bring them within the sphere of their mutual chemical attraction. This is its mechanical effect. Its chemical agency is still more important. By supplying moisture at every point of the immense included space, it determines the formation of hydrous sulphuric acid, from the compound of nitric, nitrous, sulphurous, and dry sulphuric acids. No sooner is this reaction accomplished, than the nitrous gas resumes its oxygen, from the continuous atmospherical current, and becomes again fit to operate a like round of transmutations with sulphurous acid, steam, and oxygen. The nitrogen (azote), which ought to be the only residuum in a perfectly regulated vitriol chamber, escapes, by its relative lightne , at the opening c , in the roof, or, more properly speaking, is displaced by the influx of the heavier gases at the entrance-pipe. On the intermittent plan, after the consumption of each charge, and condensation of the product, the chamber was opened, and freely ventilated, so as to expel the residuary azote, and replenish it with fresh atmospheric air. In this system there were four distinct stages or periods:—1. Combustion for two hours; 2. Admi ion of steam, and settling, for an hour and a half; 3. Conversion, for three hours, during which interval the drops of strong acid were heard falling like heavy hailstones on the bottom; 4. Purging of the chamber, for three quarters of an hour. By the continuous method, sulphuric acid may be currently obtained in the chambers, of the specific gravity 1·350, or 1·450 at most; for, when stronger, it absorbs and retains permanently much nitrous acid gas; but by the intermittent, so dense as 1·550, or even 1·620; whence in a district where fuel is high priced, as near Paris, this method recommended itself by economy in the concentration of the acid. In Great Britain, and even in most parts of France, however, where time, workmen’s wages, and interest of capital, are the paramount considerations, manufacturers do not find it for their interest in general to raise the density of the acid in the chambers above 1·400, or at most 1·500; as the further increase goes on at a retarded rate, and its concentration from 1·400 to 1·600, in leaden pans, costs very little. At about the specific gravity of 1·35, in Great Britain, the liquid of the chambers is run off, by the syphon above described, into a leaden gutter or spout, which discharges it into a series of rectangular ve els made of large sheets of lead, of 12 or 14 lbs. to the square foot, simply folded up at the angles into pans 8 or 10 inches deep, resting upon a grate made of a pretty close row of wrought-iron bars of considerable strength, under which the flame of a furnace plays. Where coals are very cheap, each pan may have a separate fire; but where they are somewhat dear, the flame, after pa ing under the lowest pan of the range, which contains the strongest acid (at about 1·600), proceeds upwards with a slight slope to heat the pans of weaker acid, which, as it concentrates, is gradually run down by syphons to replenish the lower pans, in proportion as their aqueous matter is di ipated. The 3 or 4 pans constituting the range are thus placed in a straight line, but each at a different level, terrace-like; en gradins , as the French say. When the acid has thereby acquired the density of 1·650, or 1·700 at most, it must be removed from the leaden evaporators, because, when of greater strength, it would begin to corrode them; and it is transferred into leaden coolers, or run through a long refrigeratory worm-pipe surrounded by cold water. In this state it is introduced into gla or platinum retorts, to undergo a final concentration, up to the specific gravity of 1·842, or even occasionally 1·845, in consequence of slight saline impurities. When gla retorts are used, they are set in a long sand-bath over a gallery furnace, resting on fire tiles, under which a powerful flame plays; and as the flue gradually ascends from the fireplace, near to which it is most distant from the tiles; to the remoter end, the heat acts with tolerable equality on the first and last retort in the range. When platinum stills are employed, they are fitted into the inside of cast-iron pots, which protect the thin bottom and sides of the precious metal. The fire being applied directly to the iron, causes a safe, rapid, and economical concentration of the acid. The iron pots, with their platinum interior, filled with concentrated boiling-hot oil of vitriol, are lifted out of the fire-seat by tackle, and let down into a cistern of cold water, to effect the speedy refrigeration of the acid, and facilitate its trans vas i on into carboys packed in osier baskets lined with straw. Sometimes, however, the acid is cooled by running it slowly off through a long platinum syphon, surrounded by another pipe filled with cold water. Fig. 1102. shows my contrivance for this purpose. IMG:4147767755307473660_illo1223.png:Syphon The under stopcock a , being shut, and the leg b , being plunged to nearly the bottom of the still, the worm is to be filled with concentrated cold acid through the funnel c . If that stopcock is now shut, and a opened, the acid will flow out in such quantity as to rarefy the small portion of air in the upper part of the pipe b , sufficiently to make the hot acid rise up over the bend, and set the syphon in action. The flow of the fluid is to be so regulated by the stopcock a , that it may be greatly cooled in its pa age by the surrounding cold water in the ve el f , which may be replenished by means of the tube and funnel d , and overflow at e . A manufacturer of acid in Scotland, who burns in each chamber 210 pounds of sulphur in 24 hours, being at the rate of 420 pounds for 20,000 cubic feet (= nearly 2000 metres cube) has a product of nearly 3 pounds of concentrated oil of vitriol for every pound of sulphur and twelfth of a pound of nitre. The advantage of his proce results, I conceive, from the lower concentration of the acid in the chambers, which favours its more rapid production. The platinum retort admits of from 4 to 6 operations in a day, when it is well mounted and managed. It has a capital of platinum, furnished with a short neck, which conducts the disengaged vapours into a lead worm of condensation; and the liquid thus obtained is returned into the lead pans. Great care must be taken to prevent any particles of lead from getting into the platinum ve el, since at the temperature of boiling sulphuric acid, the lead unites with the precious metal, and thus causes holes in the retort. These must be repaired by soldering-on a plate of platinum with gold. Before the separate oven or hearth for burning the sulphur in contact with the nitre was adopted, this combustible mixture was introduced into the chamber itself, spread on iron trays or earthen pans, supported above the water on iron stands. But this plan was very laborious and unproductive. It is no longer followed. One of the characters of the good quality of sulphuric acid, is its di olving indigo without altering its fine blue colour. Sulphuric acid, when well prepared, is a colourle and inodorous liquid, of an oily aspect, po e ing a specific gravity, in its most concentrated state, of 1·842, when redistilled, but as found in commerce, of 1·845. It is eminently acid and corrosive, so that a single drop will communicate the power of reddening litmus to a gallon of water, and will produce an ulcer of the skin when allowed to remain upon it. If swallowed in its strongest state, in even a small quantity, it acts so furiously on the throat and stomach as to cause intolerable agony and speedy death. Watery diluents, mixed with chalk or magnesia, are the readiest antidotes. At a temperature of about 600° F., or a few degrees below the melting point of lead, it boils and distils over like water. This is the best method of procuring sulphuric acid free from the saline and metallic matters with which it is sometimes contaminated. The affinity of sulphuric acid for water is so strong that, when exposed in an open saucer, it imbibes one-third of its weight from the atmosphere in 24 hours, and fully six times its weight in a few months. Hence it should be kept excluded from the air. If four parts, by weight, of the strongest acid be suddenly mixed with one part of water, both being at 50° F., the temperature of the mixture will rise to 300°; while, on the other hand, if four parts of ice be mixed with one of sulphuric acid, they immediately liquefy and sink the thermometer to 4° below zero. From the great attraction existing between this acid and water, a saucer of it is employed to effect the rapid condensation of aqueous vapour as it exhales from a cup of water placed over it; both standing under evaporation in vacuo, the water is speedily frozen. To determine the purity of sulphuric acid, let it be slowly heated to the boiling point of water, and if any volatile acid matter be present, it will evaporate, with its characteristic smell. The presence of saline impurity, which is the common one, is discovered by evaporating a given weight of it in a small capsule of platinum placed on red-hot cinders. If more than two grains remain out of 500, the acid may be reckoned to be impure. The best test for sulphuric acid, and the soluble salts into which it enters, is the nitrate of baryta, of which 182 parts are equivalent to 49 of the strongest liquid acid, or to 40 of the dry, as it exists in crystallized sulphate of pota a. One twenty thousandth part of a grain of the acid may be detected by the grayish-white cloud which baryta forms with it. 100 parts of the concentrated acid are neutralized by 143 parts of dry carbonate of pota a, and by 110 of dry carbonate of soda, both perfectly pure. Of all the acids, the sulphuric is most extensively used in the arts, and is, in fact, the primary agent for obtaining almost all the others, by disengaging them from their saline combinations. In this way, nitric, muriatic, tartaric, acetic, and many other acids, are procured. It is employed in the direct formation of alum, of the sulphates of copper, zinc, pota a, soda; in that of sulphuric ether, of sugar by the saccharification of starch, and in the preparation of phosphorus, . It serves also for opening the pores of skins in tanning, for clearing the surfaces of metals, for determining the nature of several salts by the acid characters that are disengaged, . According to the analysis of Dr. Thomson, the crystalline compound deposited occasionally in the leaden chambers above described consists of — | Sulphurous acid | 0·6387, | or | 3 | atoms. | | Sulphuric acid | 0·5290, | | 2 | | | Nitric acid | 0·3450, | 1 | atom. | | Water | 0·0733, | 1 | | Sulphate of lead | 0·0140. | | He admits that the proportion of water is a little uncertain; and that the presence of sulphurous acid was not proved by direct analysis. When heated with water, the crystalline matter disengages nitrous gas in abundance; lets fall some sulphate of lead; and the liquid is found to be sulphuric acid. When heated without water, it is decomposed with emi ion of nitrous gas and fuming nitric acid; leaving a liquid which, mixed with water, produces a brisk effervescence, consisting chiefly of nitrous gas. The following Table shows the quantity of concentrated and dry sulphuric acid in 100 parts of dilute, at different densities, by my experiments, published in the Quarterly Journal of Science, for October, 1817 :— | Liquid. | Sp. grav. | Dry. | | 100 | 1 | ·8460 | 81 | ·54 | | 99 | 1 | ·8438 | 80 | ·72 | | 98 | 1 | ·8415 | 79 | ·90 | | 97 | 1 | ·8391 | 79 | ·09 | | 96 | 1 | ·8366 | 78 | ·28 | | 95 | 1 | ·8340 | 77 | ·46 | | 94 | 1 | ·8288 | 76 | ·65 | | 93 | 1 | ·8235 | 75 | ·83 | | 92 | 1 | ·8181 | 75 | ·02 | | 91 | 1 | ·8026 | 74 | ·20 | | 90 | 1 | ·8070 | 73 | ·39 | | 89 | 1 | ·7986 | 72 | ·57 | | 88 | 1 | ·7901 | 71 | ·75 | | 87 | 1 | ·7815 | 70 | ·94 | | 86 | 1 | ·7728 | 70 | ·12 | | 85 | 1 | ·7640 | 69 | ·31 | | 84 | 1 | ·7540 | 68 | ·49 | | 83 | 1 | ·7425 | 67 | ·68 | | 82 | 1 | ·7315 | 66 | ·86 | | 81 | 1 | ·7200 | 66 | ·05 | | 80 | 1 | ·7080 | 65 | ·23 | | 79 | 1 | ·6972 | 64 | ·42 | | 78 | 1 | ·6860 | 63 | ·60 | | 77 | 1 | ·6744 | 62 | ·78 | | 76 | 1 | ·6624 | 61 | ·97 | | 75 | 1 | ·6500 | 61 | ·15 | | 74 | 1 | ·6415 | 60 | ·34 | | 73 | 1 | ·6321 | 59 | ·52 | | 72 | 1 | ·6204 | 58 | ·71 | | 71 | 1 | ·6090 | 57 | ·89 | | 70 | 1 | ·5975 | 57 | ·08 | | 69 | 1 | ·5868 | 56 | ·26 | | 68 | 1 | ·5760 | 55 | ·45 | | 67 | 1 | ·5648 | 54 | ·63 | | 66 | 1 | ·5503 | 53 | ·82 | | 65 | 1 | ·5390 | 53 | ·00 | | 64 | 1 | ·5280 | 52 | ·18 | | 63 | 1 | ·5170 | 51 | ·37 | | 62 | 1 | ·5066 | 50 | ·55 | | 61 | 1 | ·4960 | 49 | ·74 | | 60 | 1 | ·4860 | 48 | ·92 | | 59 | 1 | ·4760 | 48 | ·11 | | 58 | 1 | ·4660 | 47 | ·29 | | 57 | 1 | ·4560 | 46 | ·48 | | 56 | 1 | ·4460 | 45 | ·66 | | 55 | 1 | ·4360 | 44 | ·85 | | 54 | 1 | ·4265 | 44 | ·03 | | 53 | 1 | ·4170 | 43 | ·22 | | 52 | 1 | ·4073 | 42 | ·40 | | 51 | 1 | ·3977 | 41 | ·58 | | 50 | 1 | ·3884 | 40 | ·77 | | 49 | 1 | ·3788 | 39 | ·95 | | 48 | 1 | ·3697 | 39 | ·14 | | 47 | 1 | ·3612 | 38 | ·32 | | 46 | 1 | ·3530 | 37 | ·51 | | 45 | 1 | ·3440 | 36 | ·69 | | 44 | 1 | ·3345 | 35 | ·88 | | 43 | 1 | ·3255 | 35 | ·06 | | 42 | 1 | ·3165 | 34 | ·25 | | 41 | 1 | ·3080 | 33 | ·43 | | 40 | 1 | ·2999 | 32 | ·61 | | 39 | 1 | ·2913 | 31 | ·80 | | 38 | 1 | ·2826 | 30 | ·98 | | 37 | 1 | ·2740 | 30 | ·17 | | 36 | 1 | ·2654 | 29 | ·35 | | 35 | 1 | ·2572 | 28 | ·54 | | 34 | 1 | ·2490 | 27 | ·72 | | 33 | 1 | ·2409 | 26 | ·91 | | 32 | 1 | ·2334 | 26 | ·09 | | 31 | 1 | ·2260 | 25 | ·28 | | 30 | 1 | ·2184 | 24 | ·46 | | 29 | 1 | ·2108 | 23 | ·65 | | 28 | 1 | ·2032 | 22 | ·83 | | 27 | 1 | ·1956 | 22 | ·01 | | 26 | 1 | ·1876 | 21 | ·20 | | 25 | 1 | ·1792 | 20 | ·38 | | 24 | 1 | ·1706 | 19 | ·57 | | 23 | 1 | ·1626 | 18 | ·75 | | 22 | 1 | ·1549 | 17 | ·94 | | 21 | 1 | ·1480 | 17 | ·12 | | 20 | 1 | ·1410 | 16 | ·31 | | 19 | 1 | ·1330 | 15 | ·49 | | 18 | 1 | ·1246 | 14 | ·68 | | 17 | 1 | ·1165 | 13 | ·86 | | 16 | 1 | ·1090 | 13 | ·05 | | 15 | 1 | ·1019 | 12 | ·23 | | 14 | 1 | ·0953 | 11 | ·41 | | 13 | 1 | ·0887 | 10 | ·60 | | 12 | 1 | ·0809 | 9 | ·78 | | 11 | 1 | ·0743 | 8 | ·97 | | 10 | 1 | ·0682 | 8 | ·15 | | 9 | 1 | ·0614 | 7 | ·34 | | 8 | 1 | ·0544 | 6 | ·52 | | 7 | 1 | ·0477 | 5 | ·71 | | 6 | 1 | ·0405 | 4 | ·89 | | 5 | 1 | ·0336 | 4 | ·08 | | 4 | 1 | ·0268 | 3 | ·26 | | 3 | 1 | ·0206 | 2 | ·446 | | 2 | 1 | ·0140 | 1 | ·63 | | 1 | 1 | ·0074 | 0 | ·8154 | SUMACH (Eng. and Fr.; Schmack , Germ.); is the powder of the leaves, peduncles, and young branches of the Rhus coriaria , and Rhus cotinus , shrubs which grow in Hungary, the Bannat, and the Illyrian provinces. Both kinds contain tannin, with a little yellow colouring-matter, and are a good deal employed for tanning light-coloured leathers; but the first is the best. With mordants, it dyes nearly the same colours as galls. In calico-printing, sumach affords, with a mordant of tin, a yellow colour; with acetate of iron, weak or strong, a gray or black; and with sulphate of zinc, a brownish-yellow. A decoction of sumach reddens litmus paper strongly; gives white flocks with the pro to muriate of tin; pale-yellow flocks with alum; blue flocks with red sulphate of iron, with an abundant precipitate. In the south of France, the twigs and leaves of the Coriaria myrthifolia are used for dyeing, under the name of rédoul , or rodou .