faut, who is said to have obtained a yield of 25 per cent. instead of 10.

As already observed, the sulphur is contained only in a state of mixture in the Romagna stone, and not being in chemical combination with any substance, is easily separated by fusion. The melting point of sulphur being extremely low, fusion may be effected by hot-air or by steam, instead of in kilns or even heaps, where the excess of heat converts a large portion of the substance into sulphurous acid. Taking advantage of this property of sulphur, M. Brunfaut employs an apparatus which consists of a horizontal cylinder, containing an archimidean screw throughout its whole length. The cylinder is made to revolve more or less slowly, according to the nature of the mineral to be treated. The sulphur ore is poured in through a funnel at one end of the cylinder, and when it has sufficiently undergone the action of the apparatus it is led out at the other end. The temperature in the cylinder is maintained by hot-air or steam, which is introduced under a pressure of three atmospheres. By this machine 150 cubic metres of the mineral are reported to be disposed of in twenty-four hours. This economical method of extracting sulphur from its minerals is a matter of great importance to Italy, which is so rich in that valuable substance.Jour. Franklin Institute, Oct., 1867.-Lon. Mech. Mag., Aug. 1867.

SOLUTION OF CHLORINATED MAGNESIA.

BY ROBERT F. FAIRTHORNE.

Thinking that this preparation, from the possession of certain properties, has advantages over the solution of chlorinated soda, known by the name of "Labarraque's Disinfecting Liquid," I would suggest the following simple formula for making the same: Dissolve 8 ounces sulphate of magnesia in two pints of water. Triturate in a mortar 4 ounces and 1 drachm of chlorinated lime with an equal amount of the same fluid. Mix the solutions together and agitate occasionally.

After standing twelve hours pour off the supernatant liquid. This consists of a solution of chlorinated magnesia containing a small amount of sulphate of lime. I found, by adding solution

of caustic soda, that the precipitate produced thereby from 4 ounces of the liquid, when dried, weighed 35 (grains; therefore each ounce contains a little less than 9 grains of magnesia.

The superiority over the corresponding solutions of soda and lime as a remedial agent, consists in the base (magnesia) which it contains not being caustic in its nature. Therefore particularly adapted either for internal use or as an application to delicate tissues where the effect of chlorine or its compounds only is required.-Jour. Franklin Institute, Oct., 1867.

CRYOLITE AND ITS PRODUCTS.

BY EVAN T. ELLIS.

This remarkable mineral, which, as you will observe, is partially transparent, of a vitreous lustre, and brittle texture, is a fluoride of sodium and aluminum, containing

It is found in an immense deposit in Greenland, at Iviktout, at the head of Arksut Bay, near Cape Farewell. The first discovery was made by one of the missionaries, who carried a specimen with him to Copenhagen. Its true composition was determined by Vanquelin.

There is a bed eighty feet thick, and three hundred feet long, at the above-mentioned place.

It is frequently associated with the salts of metals, and beautiful crystals of galena, or sulphide of lead, chalybite, or brown spathic carbonate of iron, resembling spar in lustre, copper pyrites with silver, iron pyrites, &c., are found therein, arranged in masses segregated from the white, transparent, ice-like cryolite.

It remained for the "Pennsylvania Salt Company" to introduce to our country this valuable material. This energetic Company, whose works are in western Pennsylvania, has secured the privilege of using a large part of all that is mined, and has,

within two years past, imported into Philadelphia thirteen cargoes, or nine thousand tons, which have been sent to their works for manufacture.* The greater portion of this has been used for their patent Saponifier. They are now devoting their attention to the preparation of caustic soda, carbonates, and other salts of soda, sulphate of alumina, &c.

Soda is obtained from cryolite by simply mixing with lime, and subjecting to heat. The fluorine combines with the calcium, forming fluoride of calcium; while the remaining metals absorb oxygen from the air, and become alumina and soda. Carbonic acid is then passed through the solution, forming, with the sodium, a carbonate of soda, which remains suspended, while the alumina, being insoluble, is deposited at the bottom of the vessel. The carbonate of soda is deprived of its acid by means of lime in the usual manner, and thus rendered caustic, and fitted for the use of the soap-maker.

One hundred pounds of cryolite yield—

44 lbs. dry caustic soda,

The sulphate of alumina contains 2.82 of sulphuric acid to 1 equivalent of alumina, therefore this is more than a neutral salt (3. being neutral), which is very desirable for manufacturers of paper, calico printers, &c. It is also entirely free from iron, another very important characteristic.

There is another very important use to which cryolite can be applied. By a fusion of one part of cryolite with from two to four of pure silex, a beautiful glass is formed, susceptible of mould and polish, and capable of being manufactured into an endless variety of useful and ornamental articles, and probably many utensils for chemical and pharmaceutical use will be made of it. A company has been operating in Philadelphia for some time past, on an experimental scale, entitled the "Hot Cast Porcelain Company." The results have been so satisfactory

* They will import this year (1867) eight thousand tons.
The English often contains as high as 3·27 of acid.

that they have now taken a large establishment, and will be prepared to carry on the manufacture quite extensively. The cost is, at present, from ten to twenty per cent. higher than ordinary flint glass. The ware seems to be stronger than glass.-Proc. Am. Pharm. Association, 1867.

SWEET SPIRIT OF NITRE.

BY A. THEOD. MOITH.

Not many apothecaries will be able or willing to prepare sweet spirit of nitre according to the formula laid down in the Pharmacopoeia, unless they be the owners of a well appointed laboratory.

It is notorious that nearly all the sweet spirit of nitre sold by druggists for 85 cents per pound does not come up to the tests of the Pharmacopoeia. Unless a physician insists peremptorily on having Dr. Squibb's nitre, it is not likely that the apothecary will procure the proper article: as a pure article like Dr. Squibb's, which I have used exclusively for the last four years, costs $1.46 per pound, the difference is too great for most.

In this dilemma between dispensing a cheap poor article and a good one, comes to our relief, in my humble opinion, a formula by Professor Theoph. Redwood, given in the July number of the Druggists' Circular.

Struck by the rationale of this formula, I prepared it by this formula three or four times, and the spirit of nitre resulting answers fully all the tests of the Pharmacopoeia.

Any one with the slightest claim to the name of apothecary will be able to perform the task easily, cheaply, and without any risks. A retort, a glass receiver marked with a strip of paper, pasted on, to indicate 12 and 15 ounces, a Fahrenheit thermometer, besides a stove, and a stove kettle for water-bath, are all that are necessary in the way of apparatus.

Around a pencil 1 coiled loosely a cylinder of fine copper wire (No. 22 will do), 2 oz. ; remove the pencil, and introduce or slip the wire into the retort. Pour on this, through a long-necked funnel, a mixture made as follows:

To 1 pint stronger alcohol pour slowly, under constant stirring, 2 fluidounces sulphuric acid, sp. gr. 1-843, and then 2 fluid

ounces nitric acid, 1.42; place the retort in the water-bath, connect with the well-cooled receiver; place the thermometer in the water-bath, and at the temperature of 175° F. distil over 12 fluidounces. Reduce now the water in the water-bath, with enough cold water, to the temperature of 60° or 65° F., and pour through the funnel into the retort fluidounce more nitric acid, and resume the distillation till 15 fluidounces are in the receiver. This ether mix with 2 pints stronger alcohol.

Remove the copper wire from the retort, wash well, and keep it for the next operation.

The cost of the three pints of ether will be not over $1.77, and it answers all the tests of the Pharmacopoeia.

For my part, I herewith tender to Prof. Redwood my obligation for his disinterested labor and genial character.-Proc. Am. Pharm. Association, 1867.

AND

ON THE RELATIVE VALUE OF THE RHIZOMA RADICAL FIBRES OF PODOPHYLLUM PELTATUM IN THE MANUFACTURE OF PODOPHYLLIN.

BY WM. SAUNDERS.

In commerce it is well known that samples of the rhizoma of Podophyllum peltatum, freed from the radical fibres, are preferred, and command a higher price; and also that the presence of an unusually large proportion of fibres is regarded as an evidence of inferiority. This preference may, in some cases, origi nate from the fact that the fibres are often associated with a considerable quantity of dust and other foreign matter, but however clean they may be made, the prejudice still exists in their disfavor.

To determine how far this objection is grounded on any deficiency of strength in the fibres as compared with the rhizoma, the following experiments were tried:

Eight ounces of the rhizoma, carefully freed from fibres, were ground in a Swift's drug mill sufficiently fine to pass through a sieve of twenty-five meshes to the inch. Eight ounces of root fibres, free from rhizoma, were treated in a similar manner. These were each moistened with four ounces of alcohol, and packed in separate percolators. After macerating for twenty