parative ease to places which, a few years ago would have been pronounced incapable of access to the European.

Since Aden was declared a free port, the concourse of natives here from the opposite shores of Africa and from the sea-coast of Southern Arabia, has considerably augmented,-a satisfactory proof that trade is on the increase; and I am persuaded that, under judicious management, Aden bids fair to become the great mart of this part of the world. As these visitors and strangers learn more of our habits, and begin to apprehend that their own interests are in a measure bound up with ours, they will gradually lose their jealousy, and eventually become our guides to the homes which they inhabit. This nearer approach to us increases year after year, and the hope may be reasonably entertained, that the present generation of Somalis and Arabs who frequent Aden will not have passed away, before the skill and energy of Europeans shall have availed of this favourable feature to penetrate into their country and to explore its now hidden resources and treasures.

With regard to the general commerce of this region, I trust that the time is not distant, when British merchants will deem it worth while to inquire what prospects it holds out for successful speculation. America and France are before them in the field, and although I cannot assert how far their efforts have been prosperous, yet the simple fact that they are able to carry on business here and the other point which I have already stated regarding the increase of trade generally in these parts, may justly be regarded as sufficient criteria to warrant attention being called to the subject.

If the foregoing remarks shall in any degree tend to awaken interest, either in the lovers of science or in the mercantile community, and thus pave the way to the acquisition of the least benefit, the imperfect attempt of the writer will be more than compensated.

AMERICAN LARD.

BY F. CRACE CALVERT, ESQ.

DURING the numerous analyses I made some three years since of various articles of food employed in public establishments, I analysed several samples of American lard, and therefore may add to the fact already mentioned by Mr. George Whipple in your last number, that I found them to contain, in addition to starch, from 10 to 12 per cent. of water, and from 2 to 3 per cent. of alum, and about 1 per cent. of quick lime.

A few months ago I was able to ascertain that the operation is conducted in the following manner :

The fatty matters, such as they arrive from America, are melted with a little water in false-bottomed copper pans, through which circulates a current of steam. The dirt and other heterogeneous matters fall to the bottom of the pans, and the clear grease is allowed to run into a wooden vessel, when it is stirred in contact with cold water; it is then put under revolving wheels, with a thick paste made of potato starch, mixed with a little potash alum, and quick lime, which appears to facilitate the taking up of the water and starch by the fatty matter.

The cause of the American lard appearing so white, is no doubt, the great division of the fatty matter through the interposition of the starch, water, and

alumina.

The quantity of alum should be such that a small excess should remain to prevent the starch from becoming mildewed, and I believe that the manufacturer also adds it for the purpose of communicating to the lard the property of facilitating the raising and increasing the whiteness of the confectioners' paste, in which it is employed largely.

Royal Institution, Manchester, 17th January, 1853.

ON THE MANUFACTURE OF RESIN OILS.

BY F. CRACE CALVERT, ESQ.

I READ in your last number a very interesting paper on resin oil, which has led me to believe that it may be useful to some of your numerous readers to be acquainted with a simple process I have discovered of almost entirely removing from resin oil its present noxious odour, which so much prevents its application in numerous instances, where, from its cheapness, it might be employed with great advantage.

My process consists in placing 100 gallons of the oil in a copper pan, or what is better, in a pan of glazed iron, and adding thereto by degrees 35 lbs. of sulphuric acid of sp. gr. 1.345. The whole is then well stirred and gently heated to a temperature of 300°. During this operation large quantities of gas and vapour are given off, the production of which is greatly facilitated by agitating the mass. The fumes having nearly ceased to arise, the whole is allowed to cool, and a clear brown liquor is decanted from a thick carbonaceous mass, which adheres to the bottom of the vessel, and it is distilled in the ordinary way. A copper still is preferred to an iron one for this operation, as it is less acted upon by the small quantity of vitriol which remains in the oil.

With the exception of the first and last products of distillation, the whole of the bulk of the oil distilled is nearly white, and it only requires to be heated at a low temperature, or by passing through it a jet of steam, to obtain the resin oil deprived, or nearly so, of any odour.

There is a simple contrivance which can be adopted to prevent by any chance the slight amount of acid which remains in the oil from acting upon the still. It consists in suspending in the centre of the still containing the oil a basket filled with chalk, which neutralizes, as the oil is set in motion by currents, any acid it may have retained.

The advantage of obtaining this cheap oil free from odour, and enabling it to be applied to various purposes from which it is now excluded, will, I believe, more than cover the slight expense of the above process and the loss of ten per cent. of the oil experienced in the working.

Royal Institution, Manchester, 17th Jan., 1853.

SOME NOTICES OF THE HURRICANE OF 1824.

BY W. HAMILTON, M. B.

THE extensive destruction which has marked the progress of the formidable gale of the 26th and 27th of last month, that swept, with desolating fury, over the whole area of the British islands, gives an interest to the scattered details which yet survive, of the still more furious hurricane which some eight-andtwenty years ago spread ruin and desolation along the SW. coast of England, and was accompanied by a far greater and more rapid diminution of atmo spheric pressure than was observed at Plymouth upon the recent occasion, or has perhaps been ever recorded in these islands.

Having recently stumbled, by the merest accident, upon a letter, giving some account of the fluctuations of the mercury in the barometer previous to, and during the progress of that gale, which I addressed to the editor of the Devonshire Freeholder, a local paper which has long ceased to exist, within a week after the event, I may perhaps be pardoned for recalling that letter from the oblivion into which it has fallen, and endeavouring to obtain a fresh lease of existence for the few facts it contains, by offering them for insertion in the pages of the Pharmaceutical Journal. Though not strictly Pharmaceutical, such phenomena, in their results, exert so considerable an amount of influence upon the sanitary condition of society, that an investigation of their details cannot be wholly destitute of interest to the Pharmaceutical student.

66

TO THE EDITOR OF THE DEVONSHIRE FREEHOLDER.

"Sir,-The following table exhibits the state of the mercury in my barometer between nine o'clock on the morning of the 22nd inst. and the same hour on the 23rd, a period distinguished for one of the most furious and calamitous hurricanes ever witnessed, I believe, in this neighbourhood.

66

The greatest depression of the mercury, at any former period, within the last four years, was at half-past eight o'clock in the evening of the 28th of December, 1821, when it was observed by Mr. Cox, optician at Devonport, at 27.98; while, upon the late occasion, I observed it at 27.87, or 0.11 of an inch lower.

"The elevation of my barometer above that of the gentleman who publishes his weekly register in the columns of the Devonport Telegraph, appears, from a mean of the results of his and my observations, at nearly the same hours, on the 22nd and 23rd, to be 296 feet. This result I obtained by the second of M. Ramond's methods, as given in the Philosophical Magazine, vol. xxxiii., p. 97. This circumstance will account, in some degree, for the greater depression of my barometer, at the hours most nearly corresponding to the periods of his observations on the 22nd and 23rd, as published in the Telegraph.

"As my watch was faster than the true time, I cannot be certain of the accuracy of the moments of observation, but the error of time may be easily corrected by any one who may have chanced to have observed the moment of the greatest depression of the mercury, which, in my table, is stated to have taken place between five and half-past four in the morning of the 23rd.

Hoping you will pardon this intrusion on your columns, I have the honour to remain, &c., "WM. HAMILTON.

"Plymstock, 29th Nov., 1824."

From the Devonshire Freeholder of the 4th of December, from which the fore going details have been extracted, we learn that such was the force of the sea outside the Breakwater, that

"Great quantities of stones were thrown up from the south side, rolled over the top, and plunged into the Sound on the north side. The surface, which, before the gale, was nearly level, is now a complete mass of irregular stones, without form or order-the whole appearance of the erection is quite changed."

In the twenty-eight years which have elapsed since, the whole of the damage then occasioned has been repaired, and this noble structure stands among the most useful, as well as proudest trophies of human skill and perseverance; and the following testimonial to its utility, by the editor of the Freeholder, is too truthful to be omitted:

"The inhabitants of the town are greatly indebted to those who were the means of having the breakwater erected, for, had it not been for that stupendous work, which presented to the fury of the waves so great a barrier, it was generally conceived the greatest destruction would have ensued to the lower parts of the town and neighbourhood."

At Bovisand, which, from the direction of the wind, was but imperfectly protected by the breakwater, the injury sustained was, as recorded in the same paper, considerable.

"The pier," as it informs us, "sustained considerable damage; and the diving bell, which was erected there, and worked by means of machinery attached to the pier, and places adjacent, the bell vessel not being necessary, was thrown down, and partially buried in the ruins of part of the wall which was destroyed. A vessel secured to the pier, and on board of which were five men belonging to the works, was, by the fury of the gale (on the 22nd. inst.), broken adrift, and driven on shore, about a mile further in, under Stadden heights; the men were providentially saved, but most of them lost their clothes."

Deadman's Bay presented a most melancholy spectacle after the gale, the wrecks lining its beach three deep, and consisting, for the most part, of vessels of the largest tonnage, which had sought shelter within the then unfinished breakwater from the fury of the elements. During the gale of the 26th and 27th ultimo but one vessel, a schooner, which broke adrift from her moorings, was driven ashore under Mount Batten. The lowest reading of the barometer, at an elevation of about 30 feet above the mean level of the sea, which I observed, was 29.12 at a quarter past two in the morning; exceeding, by an inch and a quarter, the maximum depression observed in 1824. The following extract from my diary, though very imperfect, may be interesting for comparison with that of 1824:

WHILE recently constructing a galvanic battery, an arrangement suggested itself which I have found very convenient and easily constructed, as one wooden

screw secures an effectual connexion between twenty or more plates, dispensing altogether with brass binding-screws, mercurial cups, or soldering the joints. As any person may easily and cheaply construct an efficient and durable battery, I send you a description of my arrangement, to publish if you think it of any value. Figure 1 represents the plates of zinc; for the negative metal I use plates of cast-iron, of the same shape but a little larger, about five inches square and one-eighth thick, and made like a grating, with the bars three-eighths of an inch apart; these an iron-founder cast for me at about one penny each; but of course plates of copper, &c., may be used instead. Figure 2 is a piece of wood, the size of which must be regulated by the size and number of the plates. A is a piece very firmly fixed to this with a female screw, in which a wooden screw F works. Figure 3 is a section of 2 at the end B; the size at C to be regulated by the plates at D. Figure 4 is a strip of copper, a little narrower than the groove at C. Figure 5 is the same, bent so that the plates at D fit into E; plates of gutta percha, or varnished wood, must be prepared, the same shape as the zinc; but six inches and a half or seven inches square, and some small squares of gutta-percha, the same width as the coppers, and as thick as it is intended the plates should be asunder: the piece of wood at B is moveable, and the width of the groove C.

To arrange the battery, place an iron plate in one of the coppers at E, slide it on a little way at B, next place one of the small pieces of gutta percha in the grove; next, one of the zinc plates in the copper, fig. 7, with the wire attached as the pole of the battery; then another small piece of gutta percha; then another iron plate in the second interval of the copper, fig. 5; then a large plate of gutta percha; then another iron in the first interval of another copper, fig. 5; then another small square of gutta percha; then a zinc plate in the last interval of the first copper, and so on for the number of plates required; ending with the copper, fig. 6, as the other pole, in which, of course, will be two iron plates; when all the plates have been slid on the wood, fig. 2, replace the small piece B, and screw the whole tight together. Thus you will have a compact battery, which can be plunged at once into the liquid and removed as quickly. No dividing cells will be required, as each zinc has iron on both sides, and the gutta percha plates dividing the contiguous iron plates, will be, as proved by Faraday, effectual isolaters. The advantages of this battery are cheap materials, easy construction, great compactness, only requiring a varnished wooden trough in which it can be placed complete in an instant, and removed the moment the current is not required.

If Mr. M. Roberts's arrangement, described in Noad's Lectures, and in Lardner and Walker's Treatise is feasible, the peculiarity of which is using both sides of both plates, this battery can be so modified and the large gutta percha plates be dispensed with; an equal number of zinc and iron plates would then be required, and the middle interval of the coppers, fig. 5, be dispensed with; but although published by so respectable authorities, I doubt this arrangement, not only because I have failed myself in applying it advantageously, but A. Crosse, Esq., of Broomfield, has expressed to me his opinion of its incorrectness, and it was also, some time since, questioned in Sturgeon's Annals and in the Mechanic's Magazine.

Dunster, Dec. 11, 1852.

NOTE ON THE PREPARATION OF LIQUID GLUE.

BY M. S. DUMOULIN.

ALL chemists are aware, that when a solution of glue (gelatine) is heated and cooled several times in contact with the air, it loses the property of forming a jelly. M. Gmelin observed, that a solution of isinglass, enclosed in a sealed glass tube and kept in a state of ebullition on the water-bath for several days, presented the same phenomenon, that is to say, the glue remained fluid, and did not form a jelly.