balistal

6 Much rain.

e Much snow and wind.

and This day I caught 51 eels.

e Grievous thaws; cellars full of water,

f At nine, p. m. the therm, stood 20 below zero.

g At five, a. m. 47°,

sh Grievous thaw; much snow adr of tremola

i Much wind.

k Very heavy rain.

/ Fair.

m Sowed some seeds.

-079 and rem Heavy rain. Pat seu esd on saimio hagiti -905 11

XV. New Mode of administering Medical Electricity.

T-.

SIR,

By Mr. Gill.

do dwon Mode I JOVICS01 } .

(To Dr. Thomson.)dow and to.30..

No. 11, Covent Garden Chambers,
Feb. 20, 1819.

The following extract of a letter from a gentleman at New York to a friend of mine here, and who has kindly permitted me

to make what use of it I think proper, contains information of so much importance to humanity, and the medical and chemical world in particular, that I lose no time in communicating it to the public through your journal, as follows. It is dated Jan. 9, 1819.

"I was extremely sorry to find from your last letter that you had not recovered of your rheumatism. Have you tried elecuicity? It is found here to be a specific in all recent cases. It is, however, applied in the new manner I have once before spoken to you of; and whether I described the jar used or not, I do not now remember: for your advantage, I will now describe the mode of making it. The outside only of the bottle is coated with paper, having tin or copper extremely thin on its surface; the bottom of the bottle nor its inside has no coating. To the end of the wire which passes through the cork or cover, attach about half a yard of small brass wire so coiled up, that when it is thrust into the bottle it will expand itself against the sides. A bottle thus prepared will give shocks similarly to the tin foiled jars in this respect, that the strength is proportionable to the distance of the electrometer from the conductor; but its sensible effect is very different, as it affects the muscles of the limbs more sensibly than the joints, and it has been found to remove complaints which the common shocks would not reach."

My friend having also been kind enough to favour me with the former letter alluded to, which is dated Oct. 21, 1817; and finding that although the manner of constructing the jar is only hinted at, yet that the effects of it are more fully described; I have thought it proper to quote them as follows:

"An important improvement in medical electricity is said to be invented. It consists in pouring through the body, or diseased part, a large quantity of the electric fluid with scarcely any pain to the patient. This is effected by coating the jar with tinselled paper instead of tin foil, and by using imperfect or very weak conductors in making the circuit. The inventor has a patent for his invention, and I paid him five dollars for the secret. 1 have made some experiments on his plan, and I find the shock much modified, and sensibly different in its effect on the muscles."

I also learn from another letter to my friend, but from another correspondent in New York, and dated Jan. 9, 1819, that a "Mr. Everit has formed an establishment there for administering electricity in this new and superior manner; and the effect of which is beyond every thing that can be conceived. He has four machines in use.'

I sincerely hope that this communication will induce such of your readers as may be possessed of the necessary apparatus, fit up some jars in this novel manner; and that they will inform the public through your Annals of the results thereof; as it appears to me that the action of the electric fluid in this modification of it very much resembles that of the voltaic pile or

battery; and may very possibly afford some valuable applications of it to chemical purposes. I am, Sir,

Your most obedient servant, ei bhow
THOMAS GILL

In a postscript, dated April 24, Mr. Gill adds, that Mr. Tuther, Philosophical Instrument Maker, High Holborn, has fitted up several electrical jars in this new manner, using, however, tin foil upon paper for the coating around their outsides, instead of tinselled paper. The success has been complete the unpleasant sensations occasioned by the passage of the electric fluid from common jars being entirely done away; whilst the most powerful effects are produced.

Though medical electricity has been administered for years in this country in nearly the same manner described in the preceding communication, yet as the method has never, so far as I know, been communicated to the public, I was unwilling to withhold the preceding letter, and trust that our medical electricians in this country will be induced by it to state the result of their experience on the subject.-T.

fords XVI. On British Mathematical Periodical Works, with a Mathematical Query.

(To Dr. Thomson.)

London, Feb. 10, 1819.

C SIR, of We have several periodical publications devoted almost exclusively to mathematical subjects, which often contain productions of considerable merit; but it is much to be regretted that the subjects are generally of a trifling nature. The questions are formed without any object beyond that of ingenious exercises; they betray no extended views, no attempts to advance physicomathematical science, nor its application to the wants of society. The time and talents of the mathematician being consumed in the preparation of the means, he forgets the end till it be too late to consider it. How different was the course which Newton pursued !

21

To you, who are so well aware of the imperfect state of the application of mathematical inquiry to physical science and the useful arts, 1 need not state that there is abundance of subjects that would not only improve the student in mathematical reason+ ing, but also exercise his inventive faculties in another and not less essential part of knowledge, viz. the consideration of the premises that ought to enter into the investigation of a physical problem. It is incorrectness in this that produces the paradox ical and unsatisfactory conclusions to be met with in every department of mechanical science.291 dɔum yrov ti to momkölt

e

to While hydrodynamical science remains in its present imperfect state, there surely cannot be a want of subjects to ob There are many mechanical men who know enough of science to apply the discoveries of mathematicians, and also to direct their attention to proper objects. But, unfortunately, the works to which I allude refuse to insert any question without the solution accompanies it. Hence useful subjects never come before their correspondents. An engineer might, without much difficulty, furnish them two or three hundred, all more or less useful in his profession; and I believe most of them might either be correctly solved, or approximate answers might be obtained near enough for practice. And surely the editors of such works must always be competent judges of what is fit for insertion without the caution of having the solution with the question; and they certainly would have a better opportunity of selection were this restriction removed.

2

Being shut out by the absurd restriction above noticed, I selicit a place for the inquiry below in your Annals, and not without a hope that there will speedily arrive a time when the present method of conducting mathematical works will be done away, and free scope will be given to a spirit of inquiry that will call the powers of science into a new field of action, more honourable to itself and to the enterprising minds of my countrymen. 4.Question. What should be the thickness of a rectangular demirevetment so that it may be in equilibrio with the pressure of the earth, the earthen scarp above it making an angle of 45° with the horizon, and the revetment itself vertical?

y

In this sketch a is the re

vetment wall, and b the hadrildstes de

earthern scarp. The expe-02 16 HOBBI riments of Col. Pasley prove tale e al that the common rules are aule to tud not correct.* And it is ne-am mame Isol cessary that every circum

T

stance affecting the pressure datengnion of 918 aloeido atl of the earth be included; because the engineer, knowing the conditions of equilibrium, can better determine what will be necessary for security. I am, Sir, your obedient servant, of bas diniga & to noJEVELO yhelusineq amis JIMASONICUS.org adt to rodoneXVII. Death of Hornemann... Teradil to Baron von Zach has published an account of the death of Frederick Hornemann, a native of Hildesheim, in Lower Saxony, who was sent by the African Association in 1797 to explore the interior of Africa. Many of my readers will recollect the interesting papers published by the African Association from this enterprising traveller, and the sanguine hopes that were entertained that he would be able to penetrate to Tombuctoo. These quamento modw *Course of Mi

Military Instruction, vol. iii.

hopes have been long extinct. The following is the account of his death communicated to Baron von Zach by Captain W. H. Smith. a

Captain Smith, having sojourned for some time at the court of the Dey of Tripoli, formed an acquaintance with the Bey of Fezzan, a man of much good sense, who had lately arrived from Mourzook. Among other interesting communications respecting the interior of Africa, he informed Capt. Smith that about lo years ago he had travelled with Hornemann and his companion. They wished to return from Tripoli to Fezzan with the design of making their way south as far as the Niger, and then to go along that river as far as Tombuctoo. But Hornemann was seized with a fever, in consequence of having drunk stagnant water in too great abundance after a very fatiguing journey. He died soon after, and was buried at Aucalus. His companion continued his journey, but fell ill at Housca, where he stopped in the house of a Tripoli merchant. Attempting to proceed on his journey before being completely recovered, he had a relapse, and died at Tombuctoo.

Capt. Smith adds, that he was informed by the Pasha that all the effects of Hornemann, consisting in books, manuscripts, instruments, clothes, and several large sealed letters, had been' sent by the Dey of Fezzan to Tripoli to be deposited with the British consul. There is a possibility, therefore, that the researches of this enterprising but unfortunate traveller may yet be recovered.-(Jour. de Phys. lxxxvii. 474.)

A society has been established in London bearing the designation of the "Hunterian Society." It professes the most friendly feeling towards all similar existing institutions, and is, founded principally, but not exclusively, for the accommodation and benefit of medical men residing in the eastern parts of the metropolis.

Its objects are to concentrate the zeal and experience of a large number of respectable practitioners whose places of residence are at a distance from professional associations already existing; and to receive and discuss communications on medical and surgical subjects. It aims particularly at the cultivation of a spirit of liberal and friendly intercourse among the members of the profession within the sphere of its influence. Nu versi It consists of honorary, corresponding, and ordinary members, and already the society is honoured by the names of a considerable number of men of character and talent.

The following is the list of the officers and council for the present year:

it gui uqis ited Boo bom Hornemann