INDIGO. This valuable and very important dye is obtained chiefly from Indigofera tinctoria, Linn., which is cultivated in Bengal, Malabar, Madagascar, St. Domingo, and other places. A superior kind, imported from America and the East Indies, is obtained from Indigofera disperma, Linn.

The dye is separated by a complicated process of maceration and steeping, and is used almost universally for dyeing cloths, cotton, silk, etc.; and, when mixed with starch, it forms the 'blue' commonly used by laundresses. The chief varieties of commerce are, Bengal, Oude, Madras, Caraccas, etc.

Note on the Solubility of Oil of Bitter Almonds in Water.

337

NOTE ON THE SOLUBILITY OF OIL OF BITTER ALMONDS IN WATER.*

PY F. A. FLUECKIGER.

In most chemical handbooks it is stated that one part of oil of bitter almonds can be dissolved in thirty parts of water. The author finds this not to be correct either for the ordinary oil containing prussic acid or the oil which contains none. Neither is it the case with oil (also free from prussic acid) which has been separated from the crystalline bisulphite combination (2 (C,H,O, NaHSO1)+OH2) by means of carbonate of sodium in a current of carbolic acid, in order to remove any benzoic acid it might contain. The oil drops first begin to disappear with 250 times their weight of water, i.e., they divide up very finely in the water, and impart to it a turbid appearance. With 300 parts of water the mixture becomes clearer, but even with much more water it is not completely clear. The exact disappearance of the turbidity is not very easy to note, as it only takes place very gradually. In practice, the solubility is yet further influenced by the formation of benzoic acid and hydrobenzamide, which are both less soluble in cold water.

The solubility of the oil in water does not appear to be much increased by heat. A turbid solution, containing 1 part in 300, does not become clear in a water-bath.

These experiments induce the author to think that the statement that I part of oil of bitter almonds is soluble in thirty parts of water may have had its origin in a printer's error, and that probably it should have been 1 in 300. At any rate the latter is nearer the truth.-London

Pharm. Journal.

SHERRY WINE.

BY J. B. FRANCIS.

Spain has been for all historical times one of the most important wine producing countries of the globe. The mountains, which follow the course of its numerous rivers, offer the most favorable situations and fertile soils for the culture of the vine; its southern position insures a sufficient amount of sunshine to fully mature the grapes and bring them every year to their highest state of perfection, while the proximity of the Atlantic ocean on the one hand, and the Mediterranean on the other, brings the natural moisture necessary to the best development of the fruit.

It is in the preparation of white, dry wines, such as sherries, that the Spanish excel all other nations, and the export trade in these products, which is carried on to most parts of the world, is, perhaps, the most notable source of wealth to the inhabitants of the Peninsula.

True Sherry Wines are the products of the district of Cadiz—the most important maritime town of Spain, situated on the bay which bears its name, in the province Andalusia. Thirty miles by rail from Cadiz, on

Archiv. der Pharmacie, vol. ii., 10.

the road to Seville, the capital of the province, lies the town of Xeres de la Frontera, around which the principal vineyards are situated. A horse car, a novelty in Spain, takes the traveler from the station to the town, the population of which is about 40,000.

Xeres, or Jerez, has the same connection with sherry wine that Bordeaux has with claret, or Rheims with champagne; in fact a closer one, as it is not only the place where the wine is produced, but even the name is derived from the town; the English having first changed Xeres, the Spanish name for the wine, into Sherris, and finally into Sherry.

The vineyards lie between the rivers Guadalquivir and Guadalette, in a triangular space, measuring about twelve miles on a side.

The actual number of acres devoted to the culture of the vine in the district of Cadiz is about 25,000, while the annual production of wine is about 50,000 butts of 106 imperial gallons each.

The vineyards are principally on slopes and declivities, and in those vineyards producing the best wine, contain a soil composed of the carbonates of lime and magnesia, mixed with clay.

The grapes, which are white, are left to hang in the sun till they begin to shrivel, when they are gathered and carefully sorted for the better wines. The fruit, dusted over with plaster of paris, is placed upon large wooden platforms, where it is trodden on by men; the juice which runs from the grapes is by some producers kept separate, but by others it is mixed with that obtained by the use of the press after the treading. The juice is filled into butts, and these are transferred to the bodega or storehouse.

Here during the months of December, January and February, the must ferments. After the first fermentation is over, the liquor is racked from the lees, and each butt of new wine receives an addition of spirit, varying according to the wine, from six to ten gallons.

The common sorts are clarified and mixed with further quantities of spirit, so as to be in a condition for export eighteen months after the vintage; but the better sorts remain in the casks for two or three years before their sale can be contemplated.

When the wine is about to be exported, a small quantity of very fine old wine or solera is mixed with it, which increases the desired sherry flavor.

The ordinary wines contain a considerable amount of albuminous matter which disposes them to spoil, and therefore, in the absence of a more desirable preservative agent, a sufficient amount of brandy is added to stop all change; but it is impossible to say how much of the alcohol of any particular sherry is natural, and how much is artificial.

The best natural sherries, however, never contain more than about 12 per cent. of absolute alcohol, while inferior varieties contain as small an amount as 8 or 9 per cent., and frequently even less. Sherry, as sold in our market, contains from 17 to 23 per cent. of alcohol, so that the addition of brandy, or "fortifying," as it is called, is seen to be very

considerable.

All sherry wine is by nature of a pale color; the darker shades, or brown sherry, are produced by age, or the addition of vino de color, or boiled wine.

Good sherry wine is very scarce; at the present time it is necessary to pay $300 per butt of 106 gallons, on the spot where the wine is produced; inferior grades can of course be obtained at much lower rates, the common, ordinary wine of the country, costing only about twelve cents per bottle.

Sherry wines have one great advantage, which is, if they are of the best quality, that the older they get the better they are; but it is an error to keep low-priced wines in the expectation of their becoming good after a time; very generally the reverse is the case, and they turn out fit for nothing.

The choicest variety of sherry, and of course the highest in price, is the famous Amontillado; but the supply is not equal to the demand, nor can it be increased, as a soil similar to the little calcareous tract at Jerez, possessing like advantages of climate, is unknown.

But in other places where the real vinous basis can not be obtained, the chances of profit have lured many into the dishonest practice of adulteration. Even Cadiz has earned an unenviable notoriety, by dishonest shippers lending themselves to the frauds of London wine merchants, who, according to a recent wine circular, obtained the cheapest liquid trash they could find, to make a counterfeit, which they shipped to Cadiz, to be brought back as genuine sherry, with a bill of lading dated from that Spanish port.--The Laboratory.

TO MAKE GOLD AND SILVER INKS.

BY C. H. VIEDT.

Good bright gold, silver and bronze inks are seldom met in the market; they are almost always of a dull color, do not flow easily from the pen, and the writing remains sticky. Hence, architects and artists mostly prefer to use shell gold and shell silver (Muschel-silber), instead of the corresponding ink. The latter, however, is so much easier and safer to use, that I will describe its preparation.

For gold ink, it is best to employ genuine gold leaf, but owing to the expense, this is seldom used; sometimes mosaic gold (sulphide of tin) or iodide of lead is employed, but almost always Dutch leaf.

Owing to the relatively low price of silver, genuine silver foil is used for silver ink; false silver foil is seldom used, and is not so good. For other metallic inks, commercial bronze powders are employed. The genuine and false foils are also sold in a finely pulverized state; they are made from the waste of the goldbeaters, by rubbing it, in metallic seives, to an impalpable powder.

In consequence of the beating between goldbeaters' skin, it has particles of grease and other impurities attached to it which must be removed before it can be used for ink. For this purpose the whole sheets, or the commercial bronze powder, are triturated with a little honey to a thin magma on a glass or porphyry plate with a pestle, as carefully as possible, as the beauty of the ink depends essentially on this. The finely rubbed paste is rinsed into a thin glass beaker, boiled for a

long time with water containing a little alkali, frequently stirred, decanted, well washed with hot water, and dried at a gentle heat. By boiling this powder with water containing sulphuric, nitric, or hydrochloric acid, different shades can be imparted to it.

Next, a solution of 1 part of white gum arabic in 4 parts of distilled water is mixed with one part of potash water glass, and triturated with the requisite quantity of purified metallic powder. Gold ink will bear more liquid than silver ink, since gold covers much better; on rough paper more metal is necessary than on sized paper; on light paper more than on dark, to make the color of the ink appear equally intense.

In general, I part of foil is enough for 3 or 4 parts of the above liquid. In preparing large quantities of ink, a low porcelain measure is used for transferring it to the small glass vessels where it is to be kept, and it must be continually and thoroughly stirred, so that it will always keep well mixed. It requires frequent stirring also when in use. It is best to mix the dry powder with the liquid immediately before using. The ink can be used with a common steel pen, and flows very well when writing slowly, but it is better to use a pencil.

I consider the use of potash water glass of great importance. It greatly increases the metallic lustre on paper, prevents its looking dead, protects the writing from being discolored by the action of the atmosphere, and also prevents it from penetrating too far into the pores of the paper, without rendering it very viscid. Although the writing of itself possesses a high metallic lustre, it may be increased by gently polishing with a polishing steel. Inks made with mosaic gold, mosaic silver, iodide of lead, etc., are not nearly so beautiful.-The American Chemist.

COMBINATIONS OF GLACIAL ACETIC ACID WITH OILS. BY J. B. BARNES.

In my paper on "The Solubility of Alkaloids in Oil," it is stated that glacial acetic acid mixes with "fixed and essential oils in all proportions." Although this is true in a large number of cases, it is not so in all, and lest some readers of the Journal might infer that my statement applies to all oils, I beg leave to submit the following, showing the result of experiments made to ascertain the exact proportions in which a considerable number unite with glacial acetic acid.

The minimum combining proportions of the following five commercial samples of oil I find to be: