Spices and How to Know Them

It has been said that preliminary extractions of the material with the best ether is necessary to remove oil and other substances, not tannin on which permanganate may act; ordinary ether will not answer, as it contains so much alcohol and water as to dissolve some of the tannin. The substance freed from ether should be extracted with boiling water and the extract made up to such dilution that 10 CC. is equal to about 10 CC. of the thirtieth normal,—permanganate solution used. The titration must be performed slowly to insure accuracy, the permanganate being run in at the rate of not more than a drop in a second, or three drops in two seconds. The eye must become accustomed to the bleaching of the indigo used, and select some one tint of yellow, as the end of reaction is then possible to duplicate. That part of the material analyzed, which is insoluble in acid and alkali of certain strength after treatment for a definite length of time, at a definite temperature, is called _crude fiber_, and it may be described as follows: Select two grains of substance 200 CC. of 5 per cent. hydrochloric acid; steam bath two hours, raising the liquid to a temperature of 90 degrees to 95 degrees C. filtration on linen cloth, washing back into beaker with 200 CC. 5 per cent. sodic-hydrate; steam bath two hours, filtration on asbestos, washing with hot water, alcohol, and ether, drying at 120 degrees, weighing, ignition and crude fiber from loss in weight. REAGENTS AND APPARATUS (1). Hydrochloric acid whose absolute strength has been determined. (a). By precipitating with silver nitrate and weighing the silver chloride. (b). By sodium carbonate, as described in Fresenius Quantitative Analysis, second American edition, page 680. (c). by determining the amount neutralized by the distillate from a weighed quantity of pure ammonium-chloride boiled with an excess of sodium-hydrate. (2). Standard ammonia whose strength relative to the acid has been accurately determined. (3). C. P. sulphuric acid specific gravity 1.83, free from nitrates, and also from ammonium sulphates, which are sometimes added in the process of manufacture to destroy oxides of nitrogen. (4). Mercuric-oxide, HgO, prepared in the wet way. That prepared from mercury nitrate cannot safely be used. (5). Potassium permanganate tolerably finely pulverized. (6). Granulated zinc. (7). A solution of 40 grams of commercial potassium-sulphide in one liter of water. (8). A saturated solution of sodium-hydrate, free from nitrates which are sometimes added in the process of manufacture to destroy organic matter and improve the color of the product. (9). Solution of cochineal, prepared according to Fresenius Quantitative Analysis, second American edition, page 679. (10). Burettes should be calibrated in all cases by the user. (11). Digestion flasks of hard, and moderately thick, well-annealed glass, which should be about 9 inches long, with a round, pear-shaped bottom, having a maximum diameter of 2½ inches and tapering out gradually in a long neck, which is three-fourths of an inch in diameter at the narrowest part and flared a little at the edge. The total capacity is 225 to 250 cubic centimeters. (12). Distillation flasks of ordinary shape, 550 cubic centimeters capacity, and fitted with rubber stoppers, and a bulb tube above to prevent the possibility of sodium-hydrate being carried over mechanically during distillation; this is adjusted to the tube of the condenser by a rubber tube. (13). A condenser with tube of block tin is best, as glass is decomposed by steam and ammonia vapor, and will give up alkali enough to impair accuracy; the tank should be made of copper, supported by wooden frame, so that its bottom is 11 inches above the workbench on which it stands. It should be about 16 inches high, 32 inches long, and 3 inches wide, gradually widening 6 inches toward the top; the water-supply tube should extend to the bottom, and there should be a larger overflow pipe above. The block tin condensing tubes should be about ⅜ of an inch inner measure and seven in number, entering the tank through holes in the front side of it near the top above the level of the overflow, and pass down perpendicularly through the tank and out through the rubber stoppers, tightly fitted into holes in the bottom; they should project 1½ inches below the bottom of the tank, and connect by short rubber tubes, with glass bulb tubes, of the usual shape, which dip into glass precipitating beakers. These beakers should project about 6½ inches high by 3 inches in diameter below, gradually narrowing above, and should be about 500 cubic centimeters capacity. The titration can be made directly in them. The seven distillation flasks should be supported on a sheet-iron shelf attached to the wooden frame which supports the tank at the front; where each flask is to stand, a circular hole should be cut with three projecting lips to support the wire gauze under the flask, and three other lips to hold the flask in place, and to prevent its moving laterally out of place while distillation is going on. Below the sheet-iron shelf should be a metal tube carrying seven Bunsen burners, each with a stopcock like those of a gas combustion furnace. These burners are of larger diameter at the top, which prevents smoking when covered with fine gauze to prevent the flame from striking back. (14). The stand for holding the digestion flask should consist of a pan of sheet iron, 29 inches long by 8 inches wide, on the front of which is fastened a shelf of sheet iron as long as the pan, 5 inches wide and 4 inches high. In this are cut six holes 1⅝ inches in diameter. At the back of the pan is a stout wire running lengthwise of the stand, 8 inches high, with a bend or depression opposite each hole in the shelf. The digestion flask rests with its lower part over a hole in the shelf and its neck in one of the depressions in the wire frame, which holds it securely in position, and heat should be supplied with Bunsen burners below the shelf. THE DETERMINATION One gram of the substance to be analyzed is brought into a digestion flask with approximately 0.7 grams of mercuric-oxide, and 20 cubic centimeters of sulphuric acid, and the flask is placed on the frame described in an inclined position, and heated below the boiling point of the acid for from five to fifteen minutes, or until frothing has ceased. The heat is then raised until it boils briskly. No further attention is required until the contents of the flask have become a clear liquor, which is colorless, or, at least, has only a very pale straw color. The flask is then removed from the flame, held upright, and, while yet hot, potassium permanganate is dropped in carefully and in small quantities at a time until, after shaking, the liquid remains of a green or purple color. After cooling, the contents of the flask are then transferred to the distilling flask with water, and to this 25 cubic centimeters of potassium-sulphide solution are added, 50 cubic centimeters of the soda solution, or sufficient to make the reaction strongly alkaline, and with a few pieces of granulated zinc. The flask is at once connected with the condenser and the contents of the flask are distilled until all of the ammonia has passed over into the standard acid contained in the precipitating flask previously described and the concentrated solution can no longer be safely boiled. This operation usually requires from 20 to 40 minutes. The distillate is then titrated with standard ammonia. The use of the mercuric-oxide in this operation greatly shortens the time necessary for digestion, which is rarely over an hour and a half in the case of substances most difficult to oxidize, and is more commonly less than an hour. In most cases the use of potassium permanganate is quite unnecessary, but it is believed that in exceptional cases it is required for complete oxidation, and, in view of the uncertainty, it is always used. Potassium-sulphide removes all mercury from solutions and so prevents the formation of mercuro-ammonium compounds which are not completely decomposed by soda solution. The addition of zinc gives rise to an evolution of hydrogen and prevents violent bumping. Previous to use, the reagents should be tested by a blank experiment with sugar, which will partially reduce any nitrates that are present which might otherwise escape notice. This method cannot be used for the determination of nitrogen substances which contain nitrate or certain albumenoids. These methods of analysis are suitable to all spices and have been used with them. They are but a general process, however, and are dependent for their value on uniformity in the way they are carried out and the manner in which peculiarities of proximate composition in different spices are considered in drawing conclusions; determinations of particular substances, such as piperine, require, however, modifications, which must be described when discussing the analysis of each separate spice. The chemical composition of olive stones and cocoanut shells is about as follows: Water, 5.63 6.15 Ash, 4.28 2.15 Fiber, 41.33 37.15 Albumenoids, 1.56 1.25 Nitrogen, .25 .20 ------------------------------------------------------------------------ [Illustration: BLACK PEPPER (Piper Nigrum) 1 Malabar 2 Acheen or Sumatra 3 Mangalore 4 Singapore 5 White, from Penang, with all three coats removed 6 White, with one coat removed 7, 8 Parts of spikes 9, 10 Fruit 12 Ovary with stamens 13 Stamens 14 Portion of spike 15 A flowering twig] CHAPTER IV BLACK PEPPER FRENCH, _Poivre_; German, _Pfeffer_; Italian, _Pepe Nero_; Spanish, _Pimienta_; Portuguese, _Pimenta_; Cyngalese, _Gammaris_; Javanese, _Maricha_; Persian, _Filfll-Seeah_; Hindoostanse, _Gol-mirch_. Pepper (Piper) Nigrum, a name employed by the Romans, and derived by them from the Greek word _peperi_; the Greeks in their turn must have derived it from the Hindoos. Botanically it is applied to the typical genus plant of the natural order _piperaceae_. Of all the varieties of spices used as a condiment, pepper is the only one which grows on a climbing vine, and there is no kind of spice better known or more esteemed or more extensively used than pepper. Its consumption is enormous.