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number of this Journal, page 390, we have noticed the discovery of green felspar at Beverly in this state. The specimens first found were met with in a stone wall; it was ascertained that the materials for the construction of the wall were taken from the common, or parade ground of Beverly, many years ago. Application was made to the proper authorities for permission to open the ground and make a thorough examination. The result of this undertaking has been highly satisfactory. The green felspar has been found in narrow veins traversing sienite, accompanied with crystals of zircon, and some other substances, the nature of which has not as yet been satisfactorily determined.

The crystals of zircon have an amber-brown colour, a resinous and oily lustre, with a fracture somewhat conchoidal and foliated. The cleavages, in some of the crystals, are tolerably distinct and indicate the octohedral primitive form. A few perfect octohedral crystals have been found.

The largest crystal in my possession, weighs 30 grains ths, and its specific gravity is 406; it is a four-sided prism terminated by a four-sided pyramid; the terminal planes being set upon the lateral edges of the prism.

With the reflective goniometer I find the angle of inclination 130° 12'. The angles scratch rock crystal.

The hornblend and felspar which accompany these interesting substances, very much resemble those of the zircon sienite cf Von Buch, with a specimen of which in my collection I have carefully compared it. The structure of this rock, and its geological connexions, are highly interesting. The following is Von Buch's description of the Norway zircon sienite. It is strongly distinguished from every porphyry by the magnificent, coarse granular, and sometimes large granular felspar, partly of a pearl-grey, and partly of a red colour, which always strongly characterises the blocks by its high degree of lustre. It is equally distinct from granite, sienite, or other similar granular stones, by the preponderance of the felspar. All the other ingredients seem to be sunk in this as a basis, and they often appear only occasionally; but hornblend is never wanting, and this hornblend is generally pretty characteristic and distinct; long black crystals, which possess a double foliated fracture by way of discrimination from mica-folia of mica also make their appearance but very rarely; and quartz shows itself in small grains, so as not to be altogether missed. It appears, in general, accidentally in the composition, and we search through whole hills without finding it again. Wherever the grains of the felspar meet, there remains almost always a small angular cavity into which crystals project. Among these, are the crystals of zircon, which give name to the rock. Epidote is associated with them in fine needles.

In the rock at Beverly, there is a great tendency of the component parts to assume regular crystalline forms, and a few perfect crystals of green felspar have been obtained.

Phosphate of Lime.-I have lately found a few pretty distinct crystals of phosphate of lime near the village of Stow, in this state. The crystals are disseminated in rolled masses of a coarse grained granite. They are portions of hexædral prisms, of a greenish-white colour. The fracture in the direction parallel to the base of the prism is distinctly foliated, and the powder phosphoresces on burning coals.

The same granite contains well defined crystals of beryl, and here and there a small crystal of tourmaline.

Andalusite.-This mineral I found in a rolled mass of white quartz, in small imperfect four-sided prisms, near Lancaster. The colour is a reddish-brown.

Spodumen.-A notice of this mineral has lately been published in the Journal of the Academy of Nat. Sci. of Philadelphia. I have visited the locality at Sterling, and find it very abundant. The principal rock in which it occurs is a compound of quartz, mica, and spodumen, weighing probably about thirty tons. may be called spodumen rock.

It

Cleavelandite occurs in small quantity at Sterling.(Boston Journ. of Philos. and the Arts, No. 6, May, 1824.)

MISCELLANEOUS.

8. On the Cause of the Rotatory Motion of Camphor in Water, (To the Editor of the Annals of Philosophy.)

SIR,

If your Cambridge correspondent E, A. (see Annals of last month) will look at page 51 of the first volume of Nicholson's Journal, 8vo. series, he will find that he is mistaken in supposing that no cause has been hitherto assigned for the rotatory motion of a particle of camphor when placed on the surface of water. Several eminent men, as he will there see, have turned their attention to this curious subject, amongst whom are Benedict Prevost, Venturi, and Caradori; and the results of their experiments will, I dare say, both interest and amuse your friend E. A. The paper alluded to is an abstract of M. B. Provost's inquiries on the subject, by M. Biot, who considers that we may infer from them, as an established fact, that "camphor is moved upon the surface of water by the effect of the emission of the particles which compose it; an emission that becomes perceptible to our senses by the smell which it produces, and by the repulsions which it exercises against small bodies floating upon the surface of water. As the effect resulting from these different impulses does not pass through the centre of gravity of the piece of camphor, this centre has a progressive motion, and the body revolves round it," &c. E. A. conceives the rotatory

motion to be wholly produced by the centre of gravity of the piece of camphor, and of the fluid displaced by it not being in the same vertical line. If that were so, an irregular piece of any substance capable of floating on water should, under the same circumstances, exhibit the same phenomena as a piece of camphor, which is not the case. Another, and cooperating cause must, therefore, be looked for; and there seems no reason to doubt that it is correctly assigned in M. Biot's abstract. Yours, F. B.

9. Improvement in Clocks.

The public papers, sometime since, contained information of an improvement in timekeepers, invented by Mr. Dyer, of this city. We hope hereafter to furnish our readers with a more particular account of this invention than is contained in the following brief notice :

The most important feature in this improvement consists in the application of the spiral teeth to the wheel-work of clocks, and in this the pinion is reduced to a single tooth. By this happy idea, Mr. Dyer has greatly reduced the wheel-work necessary to a clock, and the friction is diminished in a still greater degree; as all who are acquainted with the spiral gearing are aware that the point of contact, between two wheels with spiral-teeth, always coincides with the line of centres. Mr. Dyer has also contrived a very ingenious method of suspending the pendulum, in place of the spring, or knife-edge suspension. This method is to hang the mass constituting the pendulum to a plane, the under surface of which rolls at every oscillation upon a fixed convex body. He proposes to give such a curve to the convex surface, that the pendulum, in vibrating, shall be accelerated at every moment of its descent by a force proportional to the arch between it and the lowest point; this condition being required to render the vibrations isochronal. Mr. Dyer has not yet demonstrated the curve necessary to obtain this result; but from the constant variation of the centre of oscillation, in a pendulum suspended in the above method, the cycloid is not the curve required. He is aware that his suspension cannot be executed with such accuracy as to render the vibrations perfectly isochronal; but he may undoubtedly obtain a near approximation to a curve which would render them so.-(Boston Journ. of Philosophy and the Arts, May, 1824.)

10. Method of cleaning Gold Trinkets, and of preserving engraved Copper-plates.

The method used by artists for cleaning gold trinkets is the application of a mixture of neutral salt, intended to disengage nitric acid, with the assistance of heat. Dr. Mac Culloch recommends instead to boil the trinkets in water of ammonia,

which dissolves the metallic copper of the alloy to a certain depth on the surface, so that after the operation the metal is in fact gilded, nothing but pure gold being visible. In this process the waste of gold, which is dissolved by the acid, in the process usually employed, is avoided.

Dr. Mac Culloch observes, "that it is an unaccountable omission of chemists not to have observed that metallic copper is soluble in ammonia. The solution takes place rapidly in the heat at which the water of ammonia boils.”

Copper-plates are apt to be injured by laying by; a thin coat of oxide forms on the surface, which is rubbed off by the hand of the workman in the first inking, when the plate is again called into use; and by repetition of the formation of oxide, and its removal, the fine lines on the plate are soon injured, and ultimately obliterated. Dr. Mac Culloch recommends the application of common spirit varnish to the surface when the plate is laid by; it is easily applied, and can be removed when requisite by spirit of wine.-(Edinburgh Journal of Science.)

ARTICLE XV.

NEW SCIENTIFIC BOOKS.

PREPARING FOR PUBLICATION.

The Fourth Volume of the New Series of the Memoirs of the Manchester Literary and Philosophical Society.

A Compendium of Medical Theory and Practice, founded on Dr. Cullen's Nosology, which will be given as a Text Book. By D. Uwins, MD. in a duodecimo volume.

Muscologia Britannica: containing the Mosses of Great Britain and Ireland. By W. J. Hooker, FRS. ASL. &c. and T. Taylor, MD. MRIA. FLS. &c. 8vo. With Plates.

Mr. Swainson will speedily publish in an octavo volume, with six Plates of the most beautiful humming Birds of Mexico, the " Zoology of Mexico," illustrated by general Remarks and scientific Descriptions of the Animals collected by Mr. Bullock; to whose Travels the work is intended as an Appendix.

JUST PUBLISHED.

Wade's Observations on Fever. 8vo. 4s.

Woodford's Catalogue of Phænogamic Plants in Edinburgh. 12mo.. 3s. 6d.

Harrison's Surgical Anatomy of the Arteries. Vol. I. 12mo. 5s. Sandwith's Introduction to Anatomy and Physiology. 12mo. 9s. The Butterfly-Collector's Vade-Mecum. 12mo. 5s.

Stevenson's Historical Sketch of the Progress of Discovery, Navigation, and Commerce, from the earliest Records to the beginning of the 19th Century. 8vo. 14s.

Otter's Life and Remains of the Rev. E. D. Clarke. 4to. 31. 3s. The Encyclopædia Metropolitana, Part XII. containing, among other subjects, the completion of the article on Magnetism, Electromagnetism, and Electricity; and from CAP to CHI in the Miscellaneous Division.

ARTICLE XVI.

NEW PATENTS.

J. Crosby, Cottage-lane, City-road, for his improvement in the construction of lamps or lanterns, for the better protection of the light against the effects of wind or motion.-May 5.

J. Viney, Shanklin, Isle of Wight, for improvements in water-closets. -May 6.

W. Cleland, Leadenhall-street, for his improvement in the process of manufacturing sugar from cane juice, and in refining of sugar and other substances.-May 6.

J. T. Paul, Charing Cross, mechanist, for improvements in the methods of generating steam, and in the application of it to various useful purposes.-May 13.

J. Potter, Smedley, Lancashire, spinner and manufacturer, for certain improvements in looms.-May 13.

J. Perkins, Fleet-street, engineer, for his improved method of throwing shells and other projectiles.-May 15.

W. Church, Birmingham, for improvements in the apparatus used in casting iron and other metals.-May 15.

J. H. Ibbetson, Smith-street, Chelsea, for improvements in the manufacture of gas.-May 15.

L. W. Wright, Wellclose-square, engineer, for improvements in machinery for making pins.-May 15.

J. Luckcock, Round Cottage, Edgebaston, near Birmingham, for his improvement in the process of manufacturing iron.-May 15. W. H. James, Cobourg-Place, Winson-green, near Birmingham, engineer, for his improved method of constructing steam-carriages.May 15.

T. Parkin, Bache's-row, City-road, merchant, for improvements in machinery for printing.-May 15.

J. Dickinson, Nash Mill, Hertford, for his method of cutting cards. by machinery, and also a process for applying paste or other adhesive matter to paper by means of machinery.-May 20.

J. Cook, Birmingham, gun-maker, for improvements in the method of making and constructing locks for guns, pistols, and other firearms.-May 20.

T. Marsh, Charlotte-street, Portland-place, saddler and harnessmaker, for an improvement in the making of saddles.-May 20.

J. Viney, Shanklin, Isle of Wight, for his method of supplying water or fluids for domestic or other purposes in a manner more extensively and economically than has hitherto been usually practised.-May 22. B. Black, South Molton-street, Hanover-square, lamp manufacturer, for his improvement on carriage-lamps.-May 25.

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