understood that I have been informed, that a weak solution of silica has been added to plaster of Paris, for the purpose of hardening the same; and I mention this circumstance, in order to state, that I do not claim the employment of a solution of silica for cementing such calcined matters, which are themselves used as cements, as they are not so suitable for the purpose of combining with silicious paste or cement. And I would wish it to be understood, that what I claim is,

Firstly, the mode of manufacturing artificial stone for grinding, and other purposes, by cementing broken or pulverized stone, sand, earthy or metallic matters, with a solution of silica; and,

Secondly, I claim the subjecting artificial stone, produced by the aid of a solution of silica, with broken or pulverized stone, sand, or earthy or metallic matters, to hydraulic, or other mechanical pressure, in moulds.—In witness, &c.

Enrolled April 22, 1845.

FREDERICK RANSOME.

Specification of the Patent granted to WILLIAM OXLEY ENGLISH, of Kingston-upon-Hull, Distiller, for Improvements in the Distilling of Turpentine and Tar, and Rectifying Volatile Spirits and Oils.-Sealed Nov. 25, 1844.

To all to whom these presents shall come, &c., &c.My invention consists,

Firstly, in distilling turpentine and tar at a low temperature; and,

Secondly, in rectifying the spirits from turpentine and tar, and other volatile spirits and essential oils, at a low temperature; but, in order that the invention may be more clearly understood, I will proceed to describe the means pursued by me for carrying out my invention.

When distilling turpentine or tar, I place a quantity in an ordinary retort, having a worm and receiver attached thereto; and I apply an air-pump, for the purpose of exhausting from such retort the atmospheric pressure. This air-pump may be applied either at the top of the retort, or to the worm, or to the receiver, whichever is

most convenient; and it will be found in working, that the spirit will flow over at a lower temperature than when distilling according to the ordinary plan. In rectifying spirits and oils, I apply the air-pump to the most convenient part of the apparatus, for the purpose of exhausting the atmospheric pressure from the spirits under operation, from which the same advantage will arise as when distilling.

Having thus described the nature of my invention, and the manner of performing the same, I would have it understood, that I do not claim distilling generally where the atmospheric pressure is withdrawn from the vessel in which the distillation takes place; nor do I confine myself to the precise details herein described, or to the means of drawing off the atmospheric air, as other means may be employed for that purpose. But what I claim is,

Firstly, the distilling turpentine and tar, when the atmospheric pressure is withdrawn from the apparatus in which the distillation takes place; and,

Secondly, I claim the rectifying volatile spirits and oils, in apparatus with the atmospheric pressure drawn therefrom. In witness, &c.

Enrolled May 25, 1845.

WILLIAM OXLEY ENGLISH.

Specification of the Patent granted to ALPHONSE Le Mire DE NORMANDY, of Dalston, in the County of Middlesex, Gentleman, for Improvements in purifying Lac, and in converting Lac into Shellac.-Sealed December 7, 1844.

To all to whom these presents shall come, &c., &c.— My invention consists,

- Firstly, in a certain process of ridding lac of the impurities which it contains, such as twigs, or branches, dust, dirt, and other matters with which it may be either naturally, accidentally, or designedly mixed, and to convert it into pure lac, or into shellac.

Secondly, in the manufacture of shellac from seed lac, block lac, roll lac, or lac pieces, and for the reconversion into shellac of such lac which, having been formerly in the state of shellac, has become clogged, or run together in

blocks or pieces on their journey, or otherwise, and the processes I effect in the following manner:

The lac first described, and which it is intended to rid of impurities, is put into a sieve, the fineness of which is proportioned to the nature and size of the impurities to be removed from the lac, and the whole is to be immersed in alcohol, or other menstruum, in which lac is soluble, but which after evaporation leaves the lac unaltered in respect to its properties. The lac in the sieve, immersed in the solvent, as just said, is left therein until dissolved. To expedite the process, heat may be applied until the lac is dissolved. The heat is, I conceive, best applied by means of steam-pipes, or by Perkins's patent hot-water pipes, as by such means the heat is more under control than by a naked fire; but other modes may be applied, and the vessel into which the menstruum is put containing the lac in the sieve is preferable to be in the form of a still, provided with its worm-tub so as to be able to condense the vapours which may arise during the dissolving period. When the lac is completely dissolved the sieve may then be removed, when it will be found to contain the impurities only, the dissolved lac having filtered through. Heat being now applied to the still containing the filtered solution of lac, the alcohol or other menstruum will evaporate and may be collected separately, and will thus leave the purified lac in a melted and dry state, when it may be converted into shellac by letting it fall whilst thus melted upon a pair of revolving smooth metal rollers, the surfaces of the rollers being keep constantly moist and cool with water, and the passing of the lac between the rollers will press the lac into a thin sheet, which I allow to slide down an incline plane of sheet iron till cool, which I have found to require about forty feet, placed so that the sheet lac will slide slowly down. The alcohol or other menstruum collected from the still may be used again.

With respect to the second process, namely, the conversion of block lac and other kinds of lac into shellac, I proceed as follows:-A coil or coils of pipes containing steam at a pressure of about 50lbs. to the inch, or circulating water as in Perkins's patent apparatus at a temperature of about 260° Fahrenheit, but which is not to exceed 300° Fahrenheit, is or are placed over a pair of revolving rollers as above explained. The coils I consider best to be coiled into the shape of a funnel or cone, the

sides of which are inclined towards each other at an angle of about 60°, and the space between each coil I have found best to be about a quarter of an inch. By putting the lac to be treated within the funnel formed by these coils the lac is melted, and falling in that state upon the rollers above mentioned whilst revolving becomes converted into shellac. This apparatus may also be employed for purifying lac instead of the process first mentioned, namely, by dissolution in the proper menstruum, but in that case the inside or the outside of the coils of pipe is to be covered with wire cloth of the suitable fineness so as to fit the coil of pipes, by which means the impurities of the lac may be retained therein, the lac only passing through when melted, and thence falling on the rollers by which it is converted into shellac.

Having thus described the nature of my invention, and the means of performing the same as practised by me, I would wish it to be understood, that I do not confine myself to the details herein described, so long as the peculiar character of either part of my invention be retained. But what I claim is,

Firstly, the purifying lac by solution or heat, and passing it through a sieve to separate it from impurities, and converting the lac into shell, as above described; and,

Secondly, I claim the converting lac into shellac, by melting, aided by rollers, and cooling the sheet, or shell lac, as above described.-In witness, &c.

ALPHONSE LE MIRE DE NORMANDY.

Enrolled June 7, 1845.

Specification of the Patent granted to SAMUEL CUNLIFFE LISTER, of Manningham, in the County of York, Worsted Spinner, for Improvements in preparing and combing Wool.-Sealed Sept. 27, 1844.

To all to whom these presents shall come, &c., &c.— My improvement in preparing wool consists in passing wool through a screw gill before being combed, as I find it very beneficial in opening out the staples, and separating the fibres of wool, and, at the same time, obtaining an endless sliver, ready for filling on to the combs.

My improvement in combing wool consists in causing

the saddle comb to recede at the time that the revolving combs are passing through the wool, and thereby relieving the strain upon the wool. I have not thought it necessary to show drawings, as it is a matter of easy application to the machines now in use, and can be done in a variety of ways, that any mechanic having the idea given would easily apply.-In witness, &c. SAMUEL CUNLIFFE LISTER.

Enrolled March 27, 1845.

Specification of the Patent granted to JAMES NAPIER, of Hoxton, in the County of Middlesex, Dyer, for Improvements in treating Mineral Waters to obtain Products therefrom, and for separating Metals from other Matters.-Sealed Oct. 22, 1844.

To all to whom these presents shall come, &c., &c.— The first part of my invention has reference to the treatment of mineral waters, impregnated with copper and iron. I am aware that such waters are at present treated, in order to obtain the copper contained in them; and this is done by placing therein pieces of iron, by which the copper is thrown down as a precipitate. The waters, after undergoing this process, are let out, and the precipitate of copper is obtained, mixed with a large quantity of peroxide of iron. In this process, seven parts by weight of iron should substitute and reduce eight parts by weight of copper; but in practice, the destruction of iron averages ten times the amount of copper obtained.

The water, after the copper has been abstracted, and which contains the iron in solution, is allowed to run into pits or large reservoirs, where the iron absorbs oxygen from the air, a small quantity being thus precipitated as an oxide, and then collected and sold as ochre; after which the water is allowed to pass away. The cause of the great destruction of iron has been found to result from the existence of that metal originally in the water, in the state of what is known to chemists as a persulphate, which salt has the property of dissolving almost all metals; so that by its reaction upon the iron used to precipitate the copper, the loss is occasioned; the waters