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which, among other particulars, we have an account of the diftreffes of the epifcopal clergy in North America, occafioned by the defection of the colonies.

III. A Wedding Sermon: being the fubftance of a Difcourfe delivered at Glafs-house Yard, on May 14, 1775, preached by particular Defire, and now published at the Request of the Bridegroom, and others who heard it. By R. Elliot, A. B. and formerly of Bennet College, Cambridge. 8vo. 6d. Johnson.

This plain lecture to new-married perfons is better adapted for the clofet than the church: for it may be read in private-that is by very ferious people-without a fmile or a blufh; whereas in the church it probably occafioned both.

IV. Preached at Oxendon-street Chapel, Aug. 11, 1776, on the Deceafe of the late Matthew Matty, M. D. of the Royal College of Phyficians, London; principal Librarian of the British Mufeum; Secretary to the Royal Society, &c. By Charles Peter Layard, A. M. Fellow of St. John's College, Cambridge, 4to. I S. Robfon.

V. Peter's Confeffion. A Sermon. By Thomas Adam, Rector of Wintringham in Lincolnshire. 12mo. 6d. York printed, and fold by Rivington, &c. in London. 1776.

What is here ftyled the confeffion of Peter, is the declaration made by that difciple, Matt. xvi. 16. "Thou art the Christ, the son of the living God." It is a well adapted difcourfe.

VI. At the Anniversary Meeting of the Natives of the County of Wilts, in St. Auguftine's Church, Briftol, Aug. 8th, 1776. By Matthew Frampton, LL. D. Rector of Bremhill, &c. and Chaplain to the Earl of Suffolk. 4to. Is. Cadell, &c.

A Charity Sermon, (and a good one) for the promotion of the Wiltfhire Society; by whofe benevolence diftreffed lying-in women, and other perfons, are occafionally relieved, and poor boys apprenticed. VII. The Origin of confecrated Churches, and the Benefits of public

Worship: a Sermon preached at the opening of the Parish Church of Clapham, in the County of Surry, June 9, 1776. By Samuel Glaffe, D. D. F. R. S. and Chaplain in ordinary to his Majefty. 8vo. 6d. Rivington, &c.

A plain and pertinent exhortation to the duties of public worship, well adapted to the occafion of its delivery. VIII. On the much lamented Death of John Winter, Efq; who was upwards of Thirty Years in the Army: he departed this Life October 5, in the 62d Year of his Age. By Richard Winter. 8vo. 6 d. Buckland.

IX. Before the Univerfity of Cambridge, October 25, being the Anniversary of his Majefty's Acceffion to the Throne. By Richard Watfon, D. D. F. R. S. Reg. Prof. of Divinity in the University of Cambridge. 4to. I s. White, &c.

For whom an handfome fubfcription has been lately raised by the clergy of this kingdom.

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ART. I. PHILOSOPHICAL TRANSACTIONS of the Royal Society of London. Vol. LXVI. For the Year 1776. Part 1. 4to. 7 s. 6d. fewed.

Davis.

EXPERIMENTAL PHILOSOPHY.

Article 12. An Account of fome Attempts to imitate the Effects of the Torpedo by Electricity. By the Hon. Henry Cavendish, F. R. S.

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HOUGH the late experiments made with the torpedo have left very little room for doubt, that the concuffion given by that fish is produced by the fame agent that gives the fhock in an electrical explosion; yet there are fome circumftances attending the torpedinal concuffion, which it is difficult to reconcile to the fuppofition that it is produced by the electric fluid. One of thefe difficulties, and indeed the principal, is, that the fish is able to give a fhock when he is in the water, and confequently furrounded by a medium, through which the electric fluid is known to be tranfmitted with the greatest facility.

It has likewife been difficult to conceive why the shock of the torpedo, fuppofing it to be produced by the electric fluid, fhould not, like that of an electrified jar, be accompanied with the appearance of light, or fparks; or fhould not exhibit fome figns of attraction or repulfion. Indeed, it appears from Mr. Walsh's experiments that no light could poffibly accompany the fhock of the torpedo; because this fhock could never be made to pass through the leaft fenfible space of air, or the Imalleft interruption made in the circuit; not even through the imperceptible interval between the links of a flender brass chain, apparently in contact with each other. Nor are the moft delicate pith balls, or other light bodies, in what manner foever applied, in the leaft degree affected, at the time of the shock. E e

VOL. LV.

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Thefe difficulties the Author has endeavoured to remove, firft by fome ingenious reasonings, à priori; and afterwards by others drawn from the phenomena prefented by an artificial torpedo which he has conftructed; and by means of which he has, beyond expectation, imitated the effects produced by the living animal. We fhall first give a general, though neceffarily incomplete, view of the Author's reafonings on this fubject, previous to his experiments made with the artificial torpedo.

With respect to the difficulty of conceiving how the torpedo can give a fhock, when furrounded by fo good a conductor as water; he obferves that thofe electricians are mistaken, who fuppofe that the electric fluid will only pass along the shortest and beft conductors. When different circuits are made between the pofitive and negative fides of a charged jar; fome parts of the electric fluid will pafs along each of them: though the greater quantity will pass through thofe in which it meets with the leaft refiftance. No one doubts that iron wire is a better conductor of electricity than the human body: yet if a person takes hold of one end of a very long and flender iron wire, with one hand, and applies it to the external coating of a large and highly charged jar; and then difcharges the jar by applying to its inner coating the other extremity of the wire held in the other hand; the electric matter will not all pals along the wire: a part of it will pass through his body, and give him a fenfible fhock. In a fimilar manner, a perfon may receive a part of the fhock given by the torpedo in water, by holding one hand on the lower furface of an electric organ, and the other on the upper; or by applying his hands to other parts of the fish; or by dipping them into the water, fo that one hand is nearer to the upper furface of the electric organs than the other: and yet the greater part of the fhock, or charge, may pafs at the fame time in all directions over the furface of the fifh, or through the subftance of its body, or through the water contiguous to it.

With respect to the next difficulty, relating to the absence of light in the fhock, and its incapacity to pafs through the fmalleft fpace of air; the Author obferves that a large electrical battery will give a confiderable fhock, though at the fame time it is fo weakly charged, that the electricity will scarcely país through any fenfible interval; and the larger the battery is, the fmaller is the space through which the fhock will pafs. He proves the truth of this principle by experiments; and then proceeds to fhew that it is not extraordinary, that the fhock of the torpedo is not accompanied with figns of attraction or repulfion for confidering the inftaneity of the fhock, a pair of pith balls fufpended from any conductor in contact with the fish, cannot have time to feparate before the electricity is diffipated, or the equilibrium reftored. He obferves further, on

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the authority of Dr. Prieftley, that on the discharge of a battery, the latter could never find a pair of pith balls, fufpended from the discharging rod, to feparate. He further adds, that there are scarce any pith balls fo fine as to feparate, when connected with a battery electrified fo weakly, that its fhock will not pass through a chain; as is the cafe with that of the torpedo.

Thefe and the Author's other reasonings acquire great additional force, from the phenomena exhibited by his artificial torpedo; the conftruction of which cannot be intelligibly described without a plate. We must confine ourselves therefore to the giving a few general obfervations relative to this artificial fish; with which the Author firft, Prometheus-like, infufing into the dead mass of lead and leather some sparks of artificial fire, was enabled to imitate pretty exactly most of the natural operations of its wonderful archetype.

From this, not unapt, reprefentative of the torpedo, the Author was enabled to receive, when it was immerfed in water, fhocks greatly resembling thofe given by the living animal. He felt fimilar concuffions likewife, when he dipt his hands in the water, at two or three inches diftance from it. And as it is affirmed that a perfon accidentally treading on the living fish when buried in the fand, is fometimes fhocked by it; the Author imitated this experiment with his artificial torpedo, and had the fatisfaction of receiving fhocks from it. In short, the events in the greater part of his experiments with this artificial fish, relative to the fhock, feem to agree fufficiently with those made by Mr. Walsh with the living animal.

The experiments which he made with this machine, relative to the circumftance of the fhock of the real torpedo not being able to pass through any fenfible space of air, appear likewife to correfpond with Mr. Walth's trials. A piece of fealingwax covered with tinfoil freely conducted a fhock from the artificial torpedo: but on making as fmall a feparation as poffible through the metal with a penknife, the fhock would not pafs. Nor would it pafs, on trying the experiment with Lane's electrometer; unlefs the knobs were brought fo near together as to require the affiftance of a magnifying glafs to be fure that they did not touch each other.

We are obliged to omit many other obfervations and experiments related in this article, which feem, upon the whole, to fhew very fatisfactorily that there appears nothing in the phenomena of the torpedo at all incompatible with electricity. And though the Author has not been able, with his artificial torpedo, to imitate completely, and in every particular, the effects produced by the living animal; the Reader will probably Tather be aftonished at the near approach which he has made E e 2

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to a refemblance with the original. The principal confideration in this matter is, that the quantity of electric fluid under the difpofal or command of the torpedo is extremely great; though the force with which the fifh impels it is fo imall, as not to make it pafs through any fenfible space of air. Quantity, and force, are very different confiderations. In an eight ounce vial as highly charged as poffible, the force of the electric fluid is very confiderable. with regard, particularly, to its power of darting through a given interval of air, when compared with the force of the very fame quantity, diffused through a large battery.

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Article 13. Obfervations on Refpiration, and the Ufe of the Blood. By Jofeph Priestley, LL. D. F.R.S.

In this Article the ingenious Author appears to have fatiffactorily folved one of the most difficult and important queftions in phyfiology, which, for many ages, had eluded the inveftigation of the numerous philofophers and phyficians who had before attempted the folution. The question is, what is the use of refpiration to the fupport of life; or what is that property of fresh air which renders the infpiration of it neceffary to life; while the infpiration of air, which has been too often received into the lungs, is as fatal to life as the total deprivation of it? To the folution of this question it appears that he was incidentally led, in the courfe of his researches into the properties of different kinds of air, which originally had no reference to this particular object.

In his Obfervations upon Air [vol. i. p. 78, 277. See Monthly Review, vol. li. Auguft, 1774, page 139] he had fhewn that refpiration was a phlogistic process; or that pure air was diminished by it, and rendered unfit for the fupport of life and flame; in the very fame manner as it is affected by putrefaction, the calcination of metals, and other phlogistic proceffes. He concluded therefore that the air received into the lungs in refpiration, was employed as a neceflary menftruum, to imbibe, and carry off, from the lungs, a putrid and noxious effluvium, or

that phlogifton which had been taken into the fystem with the aliment, and was become, as it were, effete.'

The Author's prefent experiments tend to prove that the blood is the prime agent in this bufinefs; or that this fluid performs the office of difcharging the furperfluous phlogiston from the fyftem. It is in the lungs that it performs this function, where it is known to be expanded over an immense quantity of furface in the veficles of that organ; and where the whole mafs is fucceffively brought nearly into contact with the air. That it does difcharge phlogiston into the air, which it proportionably contaminates; and that it receives from this fluid its

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