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a description and delineation of a rare American plant of the * Brownæz kind,' by M. P. J. Bergius. Article sth contains the catalogue of 50 plants presented annually to the Royal Society by the company of Apothecaries.
NATURAL HISTORY. In the 2d Article, Mr. Adam Walker briefly describes the petrefactions and other natural curiofities of the cavern of Dunmore Park, near Kilkenny in Ireland. In the 3d, Dr. Michael Morris gives a short account of some specimens of lead ore, containing native lead, found in a mine in Monmouthshire. The 19th Article is a table constructed by Dr. William Withering, ascertaining the principles of twelve different kinds of marle found in Staffordshire: And in the 21st Article, the Hon. Daines Barrington describes a foffil lately found near ChristChurch in Hampshire.
Papers relating to ELECTRICITY and METEORS. The 6th Article is a short extract of a letter from Mr. Kinnerfley to Dr. Franklin; in which after taking notice of the remarkable conducting quality of some kinds of charcoal, and observing that a strong line drawn on paper with a black-lead pencil will conduct an electrical shock pretty readily, he mentions the effects of a late thunder storm in Philadelphia. A floop and three houses were, in less than an hour's time, all ftruck by it. The loop, and two of the houses, were considerably damaged ; but the third, which was provided with a cylindrical iron conductor, only half an inch thick, consisting of an assemblage of several rods strongly screwed together, the leaft of which was funk s or 6 feet under ground, was preserved from all kind of injury, by means of the apparatus ; which had evidently sustained the shock, and conducted the lightning, with no other injury to itself than the melting of 6 inches and a half of the flenderest part of a brass wire fixed on the top of it. Captain Falconer was in the house during the accident, and observed the explosion to be an astonishing loud one." Article 8. A Report of the Committee appointed by the Royal Society,
to consider of a method for securing the Poud:r Magazines at
Purfleet. Article 9. Observations upon Lightning, &c. By Benjamin
Willon, F.R. S. &c. Article 1o. A Letter to Sir Jobo Pringle, Pr. R. S. on pointed
Conductors. We have already given the substance of some of Mr. Wilson's objections, offered in the 9th Article, to the report which forms the fubject of the 8th, and to a part of which he had formally expressed his dissent in writing. [See our Review for laft Month, page 386.] These objections having been maturely considered by the committee, they, in the 10th article, declare that they
fill find no reason to change their opinion, or to vary from their former report in favour of pointed conductors. The subfcribing members of this committee are the Hon. Mr. Cavendith, Dr. Watson, Dr. Franklin, and Mr. J. Robertson. Article 20. * An Account of a fiery Meteor seen on February 10,
1772,' near Berwick ; and of some new electrical Experiments. By Patrick Brydone, Esq;
Whether all the meteors that have been described and re. corded in the Philosophical Transactions have had any just pretensions to a place in that respectable collection, may perhaps be doubted. The present, however, seems juftly intitled to that rank, as well on account of its splendour and duration, as of its height; and still more on account of the data from which that height may be estimated.' It appeared in the form of a splendid Aame of a conical figure, the light of which almoft extinguished that of the moon, then about half full ; moving nearly horizontally through a space of about 30 degrees, at about the height of 50 degrees, and seemed to burst at the end of 10 or 12 seconds into a number of sparks, resembling the stars in a sky-rocket.
The Author expecting a report, had the presence of mind to take out his watch, which had a second hand; but after stopping above 4 minutes without hearing any, he rode ori. In about a minute afterwards, however, he was stunned by a loud and heavy explofion, resembling the discharge of a large mortar at no great distance, and followed by a kind of rum. bling noise like that of thunder.' On examining his watch, he found that the found had taken 5 minutes and about 7 seconds to reach him; which, according to the common computation of 1142 feet in a second, gives a distance of at least 66 miles, At a place distant about 20 miles West, this meteor, the appearance
of which was likewise followed by a loud report, was seen by two gentlemen, nearly at the same height as it was perceived by Mr. Brydone : so that its distance from the earth was probably greater than the sensible limits of our atmosphere. This phenomenon, we shall observe, as well as many others, furnishes a strong presumption that the air is not the only medium of sound : as the violent report occasioned by it originated probably in a region, where there was as near an approach to a vacuum as any that we can make with our best air pumps.
In the remaining part of this article, the Author relates fome experiments in which he charged an insulated conductor, by rubbing the back of a cat. The animal, however, not patiently submitting to the experiment, the fame effects were produced on a young lady's combing the hair of her fister's head, which, however, we should obferve, had not, like the hair of moft other young ladies, been matted together and defiled by a paste of
pomatum pomatum and powder. On causing the pointed wire of a coated vial to follow the comb, the vial was highly charged, so as to give a smart shock, and set fire to fpirits.
In these experiments, the Author's disposition of the two ladies does not appear to us to have been perfectly, scientific. The lady who performed the office of the rubbery ought not to have stood on wax; unless indeed to thew occasionally that the likewise became electrified, but with a contrary electricity, on the approach of any body communicating with the earth and the lady whose hair was combed should have been insulated, in order to produce the greatest effect.
In the 23d Article is given an account of some of the effects of a thunder storm, in which Mr. Heartly: was killed in his bed. Mrs. Heartly, who lay on his left hand, was awakened by the explofion, and found her right arm stunned and benumbed, and a little painful. Not being alarmed, however, the fell asleep, and did not discover, till the awoke in the morning, that her husband had been killed by it. Though the bed post was split into many thivers, one of which was found witbin his nightcap, no marks were discovered on any part of his body ; except that his right cheek was (welled, and his bair on that fide confiderably finged, as was the inside of his nightcap on the fame side, while no such marks appeared on its outside.
The 13th Article contains only fome thermometrical observations relating to remarkable degrees of cold observed on the Continent in 1767,1768, and. 1770, by M. J.H. Van Swinden.
CHE MI'S TRY. Article 16. Actual Fire and Detonation produced by the Contact of
Tinfoil, with the Salt composed of Copper and the nitrous Acid. By B. Higgins, M. D.
Before we give the substance of this curious experiment, it will be proper to premise a discovery of the Author's, relating to the metallic salt produced by a combination of the nitrous acid with copper ; which he found to poffets the peculiar property of taking fire, and deflagrating in a degree of heat not greater than can be borne by the hand. This quality is most conveniently fewn by twice or thrice dipping a piece of soft bibulous paper into a saturated solution of copper in spirit of nitre, and alternately drying it with a gentle heat. If the paper, thus copiously impregnated with the cupreous salt, be then held at a moderate diftance from the fire, it will deflagrate and burn to a brown calx.
The success of the following experiment depends on the ready accensibility of this metallic salt. A fufficient quantity of it in a somewhat moist state, procured by putting several pieces of thin sheet copper into a weakened spirit of nitre, is to be beaten to the fineness of basket sea salt, and strewed to the thickness of a shilling on a piece of tinfoil, twelve inches in length, and three in breadth." The foil is then to be inftantly rolled up, so as to include the falt, as it lies, between the coils. The ends being pinched together, and the whole pressed Aat and close, the following phenomena succeffively present themselves.
First, a part of the salt deliquefces, and, being impregnated with the tin, a frothing is perceived at the ends of the coil, attended with a moderate warmth, and followed by a copious emission of nitrous fumes. The heat then increases so as to become intolerable to the fingers ; and, at length, explosion and fire are perceived, which burft and melt the tinfoil, if it be very thin. Those who would repeat the experiment must consult the Author's own account of it, as the fuccess in a great meafure depends on an attention to some minute circumstances which we have not room to mention.
The Author's rationale of this process is principally founded on the abovementioned property of the cupreo-nitrous falt, or on its easy ignition in a flight degree of heat. Its acid is fupposed in part to quit the copper, and to attack the tin *; in its commenstruation with which metal, a confiderable effervescence and heat are produced, sufficient to dry the remaining undecompounded cupreous salt, and to set it on fire. The ig. nition may likewise, we imagine, be in some measure the consequence of a nitrous fulphur extemporaneously formed, by the rapid combination of the nitrous acid with the phlogiston of the tin, and which is instantaneoully kindled and diffipated in the very act of its formation.
ANTIQUITIES. Article 4. Farther Remarks upon a Denarius of the Veturian Family, &c. By the Rev. John Swinton, B. D. F.R.S. &c.
In the 58th volume of the Philosophical Transactions Mr. Swinton informed us that NI. LUFIUS, whose name occurs on this denarius, was probably one of the Italian generals in the Social war. In the present article he haftens to acknowledge and rectify his mistake, in wrongly decyphering two or three crippled Samnite. Etruscan letters at the tail of the inscription; and now declares his opinion that this supposed old soldier was really the Merriss, Merrix, or Meddix, or at least one of the
And yet the nitrous acid has a less degree of affinity to tin than to copper, the latter of which it diffolves, while it only corrodes the former ; perfeAlly dephlogisticating it, or reducing it to a compleat calx. Its violent action on the tin therefore, though already faturated with the copper, is, we apprehend, to be attributed to this circumstance; that though it has a very inconfiderable degree of affinity to the metallie earth of the tin, it attacks this metal with violence on account of its very strong attraction of pblogifton; a principle which is known to adhere to tin very laxly.
two magiftrates going under that denomination, of the city' where the med al was ftruck. We refer to the perusa! of the article itself such of our Readers as violently intereft themselves in the fame and fortunes of the Lufian Family now - brought to light; the name of which, Mr. Swinton somewhat exultingly obferves, has never yet appeared, as he apprehends, on any other antiene coins :'--a strong recommendation, doubtless, to wish for a further acquaintance with them!
MISCELLANEOUS ARTICLES. In the 7th Article Dr. R, Watson relates the result of an ex, periment made by him to ascertain the increase of heat which the bulb of a thermometer, expofed to the rays of the sun, would receive on its being painted black with Indian ink. In consequence of this coating, it rose from 108 to 118. He proposes that the bulbs of several corresponding thermometers thould be painted of different colours, and exposed at the same time to the fun ; that conjectures may be formed respecting the disposition of the several primary colours for receiving and retaining the sun's heat.
In the 17th Article are contained some observations communicated by Sir William Johnson, on the customs, manners, and language of the Northern India's of America. The 24th Ar. cicle exhibits some tables of births and burials in the isle of An glesey; and in the 26th and last, a fhort account is given of the effects attending an explosion of inflammable -air in a coal-pic near Leeds.
MONTHLY C•A TALOGUE,
For J U NE, 1774.
Tale, in Two Parts. 460. 2 s. Davies. 1774.
meaning however seems to be so good, that we wilh the Reader to pay all due attention to the following apology, which he has added by way of potscript:
It will perhaps be objected to this poem, that some of the incidents in it are not sufficiently interesting to merit the attention of the Public. To this the Author answers, That it has ever been the chief object of poetry to copy Nature and her several operations on the human mind in the most barbarous as well as the most cultivated fate of society, in the breast of the peasant as well as that of the monarch. ff, therefore, the Author has given a just copy of Natore, he apprehends it is of very little consequence that from the structure of the poem, the story, he relates, would appear to have happened at least as far back as three centuries ago, and that the characters he has introduced are not surrounded with riches or deRev. June, 1774