of olive-oil. 2. It will distinguish olive-oil from seed-oil. 3. It will indicate whether olive-oil, although of the best ap pearance, has been mixed with seed-oil. 4. It will show the quality of seed-oils. 5. Finally, it will indicate the presence of cotton in silken or woolen textures.-12 A, Sept. 9, 427.

UTILIZATION OF THE SUDS FROM THE WASHING OF WOOL.

In nothing has the advance of practical science been more clearly evidenced than in the extent to which substances formerly wasted and lost are now reclaimed and made to constitute an important element in the profits of the manu facturer. One of these applications consists in the recovery of the soap-suds from the washings of wool in woolen factories. These were formerly allowed to run down the sewers and into the streams, to the great pollution of the latter; but in Bradford, England, they are now run from the washing-bowls into vats, and there treated with sulphuric acid. The fats rise to the surface in a mass of grease a foot or more in thickness, which is carefully collected and treated in vari ous ways, mostly by distillation. The products are grease, used for lubricating the cogs of driving-wheels in the mills; oleic acid, which is worth about $160 per ton, and used as a substitute for olive-oil; stearin, worth $400 per ton, etc. It is said that some large mill-owners are now paid from $2500 to $5000 a year for these suds, which a few years ago were allowed to run to waste.-18 A, XXI., 8.

STEEL BRUSHES FOR CLEANING IRON CASTINGS.

The removal of sand, etc., adhering from the moulds to iron castings, generally accomplished by filing, is said to be effect ed far better by means of steel brushes, placed in the market by Berthold, of Dresden. They are made of thin strips of steel, in the form of ordinary scrubbers, and also in that of whitewash brushes, and are reported to remain sharp for s long time, and to be far more convenient in use than the file. -9 C, XIII., 106.

APPARATINE, A SUBSTITUTE for Gum, STARCH, ETC. Gerard has introduced a substitute for gum, starch, gelatin, etc., for finishing all kinds of fabrics of cotton, wool, or silk, and also for thickening in calico-printing, which he names

apparatine. It is said to afford very superior effects, and to impart a hitherto unattainable velvety surface, and to render transparent articles as stiff as metallic foil. It is prepared by stirring vigorously 16 parts of potato starch into 76 parts of water, and then adding, with continued stirring, 8 parts of potash or soda lye of 25°. After a few minutes the liquid clears up and forms a gelatinous mass, which is well beaten up, the quality of the apparatine being dependent on the amount of beating. It simply dries in the air without decomposition or spoiling, and without acquiring any odor, and may be formed into thin, transparent, colorless sheets resembling horn, but more flexible.-13 C, May 1, 1875, 576.

CLARIFYING AN ALCOHOLIC SOLUTION OF SHELLAC.

Peltz found that after shaking thoroughly one part of petroleum naphtha with three parts of an alcoholic solution of shellac, the liquid separated, on standing a few minutes, into an upper layer of naphtha containing the wax in the shellac, and a lower one of clear solution of shellac with but little adhering naphtha. With a solution of shellac in ninetyfive per cent. alcohol the two layers will form, as above, only after the addition of water, so that alcohol below ninety per cent. is preferable to one above it for dissolving the shellac. A solution, clarified as above, however, leaves a more brittle and less adhesive film on evaporation. This defect may be remedied by the addition of one to three per cent. of Venetian turpentine. Benzine may be substituted for the petroleum naphtha with like results.-3 B, March 11, 369.

USES OF GELATINOUS HYDRATED PHOSPHATE OF LIME.

Dr. Sace has published a memoir upon the industrial applications of gelatinous hydrated phosphate of lime, which, according to his account, precipitates coloring matter, such as a decoction of powdered cochineal, in the condition of a lac; as also the metallic oxides-among others that of copper. Its affinity for coloring matter is, if any thing, even greater than that of albumen, which it can readily replace in various fabrics. For this preparation it is only necessary to introduce the tissue in a solution of phosphate of lime and a more or less dilute hydrochloric acid; then to wring out the cloths

and place them in an alkaline color bath.-3 B, XXXVI,

374.

SCHWEITZER'S SOLVENT FOR CELLULOSE.

Professor C. Neubauer recommends the following method for obtaining the well-known cupro-ammonium solution for technical use. He prepares an oxide of copper by the precipitation of sulphate of copper solution with caustic soda, in presence of sal ammoniac. The resulting precipitate is thoroughly washed with water, first by decantation and then upon a filter, after which it is preserved under water. To prepare the cupro-ammonium solution the oxide above referred to, after thorough agitation with the water, is slowly added to a quantity of ammonia contained in another vessel. The addition of oxide is to be continued so long as the same is dissolved by the ammonia. The resulting deep-blue colored solution dissolves cotton-wool at once, and in considerable quantity.—Fresenius' Zeit. für Anal. Chem., XIV., 195.

OLEIC ACID AS A SOLVENT AND TEST FOR GUM COPAL

A very small quantity of oleic acid dropped upon a sample of gum copal, and but gently warmed, will dissolve that gum completely. It is also an excellent reagent for distinguish ing true amber from its imitation in copal.-9 C, XIII,

25.

ADULTERATION OF BEESWAX WITH PARAFFIN.

To detect this very common form of adulteration, Miller recommends that a small quantity of the suspected substance be tested to about 325° Fahr. with concentrated sulphuric acid, and upon cooling, the paraffin, if it be present, will be found upon the surface of the mixture.-Fresenius' Zeit. für Anal. Chem., XIV., 200.

BLEACHED ISINGLASS.

On account of the preference shown by consumers gener ally for thin white isinglass, the inferior dark and bloody samples are bleached chemically at St. Petersburg, and sold as of first quality, although they have naturally a yellowish cast. According to Kattus, it has been established by experience that the bleaching impairs its adhesiveness and clarifying

power; and since the bleaching agent is never entirely removed, it may also very easily affect wine injuriously when used for clarifying it, and it may prove even more objectionable for medicinal and culinary purposes, although preferred to the natural isinglass on account of its color. Besides, only bleached isinglass can be adulterated with gelatin, and recently an impure article of this kind has been largely manufactured, which can scarcely be distinguished from the bleached and but slightly opalescent genuine article, while the Astrachan isinglass, even when soiled or dark and bloody, is fully as effective as the bleached. The chief characteristics of the genuine article are its freshness of appearance and peculiar opalescence.-5 C, XL., 214.

BLEACHING SPONGES.

Sponges are said to be bleached by the following process, without the emission of injurious or unpleasant gases: They are first covered with hydrochloric acid, for the removal of calcareous matter, and, after being washed with water, are immersed for five or ten minutes in a solution of one part of potassium or sodium permanganate to forty-five of water, in which they acquire a dark-brown color, which disappears on immersing them for one or two minutes in a solution of one part of oxalic acid in fifty parts of water, with the addition of a little sulphuric acid. They are then thoroughly washed with water. The brown color acquired may also be removed without injury by repeated immersions for several minutes in very dilute sulphuric acid.-13 C, November 1, 1367.

UTILIZATION OF CHROME-ALUM.

Although the chrome-alum occurring as a refuse product in the manufacture of certain coal-tar colors is reconverted in some cases, by Strohmeyer's process, into bichromate, in many cases it is entirely disregarded, owing to the tediousness and expensiveness of that method. A new way has recently been devised, which, it is claimed, does not require evaporation of the original refuse liquid, permits the almost complete recovery of the agent employed, and furnishes a liquid ready for immediate use. The product is said to amount to twentythree and a half per cent. of the chrome-alum, so that the process may even be found profitable, aside from its use in

connection with the manufacture of aniline and alizarine.8 C, XII., 254.

MODIFICATIONS OF CHROME-ALUM.

Gernez states, as the result of experiments, that solutions of chrome-alum which have been converted into the green modification by heating to 212° never crystallize, even if supersaturated, if care is taken that not a trace of violet chrome-alum or any other alum is present, and also that they retain their green color, and it is never assumed by solutions prepared cold. Upon slow evaporation a green transparent mass is left, which gradually fills with cracks. If, however, a fragment of crystallized chrome-alum, or other alum, is introduced into the above solution, crystallization instantly be gins, and gradually violet chrome-alum crystallizes out.—15 C, XXX., 48.

REMOVING VEGETABLE SUBSTANCES FROM WOOL.

Messrs. Barral and Salvetat, in a memorial presented to the Academy of Sciences of Paris, refer to the fact that a large proportion of the wool imported from Australia and South America contains a greater or less percentage of vegetable matter mixed with it, which, of course, is injurious to its quality, and which usually resists the mechanical means of separation. An important problem, therefore, has been the destruction and elimination of the vegetable fibre by agencies that do not affect the wool. In summing up the results of their experiments, and considering those of others working in the same field, Barral and Salvetat remark that the cellulose and woody fibre can be decomposed under the action of several chemical agents, provided that the tissue, dried in the air after soaking, is then raised in a stove to a temperature of about 350° Fahr. These agencies are sul phuric acid, hydrochlorate of alumina, hydrochloric acid, nitric acid, chlorides of zinc, of iron, of tin, and of copper; nitrates of copper, of magnesia, and of iron; sulphates of tin and of alumina, etc.

PROCESS FOR COVERING COTTON WITH SILK.

A patent for effecting this object has been granted to A. Müller, the details of which are stated as follows: He makes