it occafioned a ftrong contraction in the bending muscles of my fingers, and I could not immediately let it go; but, endeavouring to difengage my hand, threw it on the ground; taking hold of it a fecond time, to return it into the tub, I was more ftrongly affected than at first, and that not only my hands and arms, but throughout my whole body; the fore part of my head and back part of my legs fuffered principally; and in the fame manner as on receiving a very fmart fhock from a highly charged phial in electrical experiments.' In all probability this must have been the gymno us electricus; but without a defcription there can be no certainty: if it be a different fpecies, it ought furely to have been described. Obfervations on the Numb Fish, or torporific Eel. By Henry Collins Flagg. We find here, as in the preceding article, no fatisfactory description of the animal: the electrical properties are fomewhat different. It is obferved to have no effect on certain conftitutions; and that a perfon labouring under an hectic fever can handle the fish with impunity; although its electrical or benumbing powers are confiderably greater and stronger than any we have before met with. The eel I obtained,' fays the Author, got out of the tub, and it was with fome difficulty I returned it, for the repeated fhocks I received through a piece of deal board 18 inches long, with which I attempted to lift it, made my arms ache very much, and for a confiderable time. I think the numbness occafioned by touching this eel continues longer than that from an electrical fhock of the fame degree of force; and I have been affured by a perfon of good fenfe and veracity, that a negro fellow, on being bantered by his companions for his fear of this eel, determined to give a proof of his refolution, and attempted to grafp it with both hands. The unhappy confequence was, a confirmed paralyfis of both arms.' Our Author concludes his account of this animal, with a promife of repeating his experiments upon it, and trying several new ones; we wish he would alfo add a defcription of it, that naturalifts may be enabled to diftinguish it from other fpecies poffeffed of the fame quality. Obfervations on the annual Paffage of Herrings. By Mr. John Gilpin. In this circumftantial account, Mr. Gilpin traces the herrings through their annual circuit, with great accuracy; he has alfo illuftrated his obfervations by a map of the Atlantic, in which the course of the fhoal is marked with precifion. By our Author's obfervations these fish are found on the eaft fide of the Atlantic, or rather in the North Sea, in the favourable month of June, about the Islands of Shetland, whence they proceed down, the Orkneys, and then dividing, they furround the British lands, and unite again off the Land's-end in September; the united fhoal then fteers in a fouth-west direction across the Atlantic. They arrive in Georgia and Carolina about the the latter end of January, and in Virginia about February; coafting thence, eastward, to New England, they divide, and , go into all the bays, rivers, creeks, and even fmail ftreams of water, in amazing quantities, and continue fpawning in the fresh water until the latter end of April, when the old fish return into the fea, where they fteer northward, and arrive at Newfoundland in May, whence they proceed in a north-west direction, and again cross the Atlantic. Mr. Gilpin has obferved, that their coming fooner or later up the American rivers depends on the warmth or coolness of the feason, that if a few warm days invite them up, and cool weather fucceeds, it totally checks their paffage, until more warm weather returns. From all thefe circumstances, our Author thinks, that a certain degree of warmth is peculiarly agreeable to them, which they endeavour to enjoy by changing their latitude according to the diftance of the fun. Thus they are found in the British channel in September, but leave it when the fun is at too great a diftance, and push forward to a more agreeable climate: when the weather in America becomes too warm, in May, they fteer a courfe to the cooler northern feas, and by a prudent change of place perpetually enjoy that temperature of climate which is beft adapted to their nature. An Account of fome Experiments on Magnetifm. By D. Rittenhouse. Conjecture and hypothefis form the greateft part of this paper. Our Author fuppofes that the magnetical particles of matter are a neceffary conftituent part of that metal which we call iron, theagh they are probably but a small proportion of the whole mafs; that thefe particles have each a north and fouth pole, and that they retain their polarity, however the metal may be fufed or wrought. In a piece of iron the magnetical particles lie irregularly, with their poles pointing in all poffible directions; they therefore mutually deftroy each other's effects. By giving magnetifm to a piece of iron, Mr. R. thinks that we do no more than arrange thefe particles, and that when this is done, it depends on the temper and fituation of the iron whether that arrangement fhall continue, that is, whether the piece of metal fhall remain for a long time magnetical or not. He fuppofes that there is a certain power, diffufed through every part of fpace, which acts on thefe magnetic particles, impelling one of their poles in a certain direction with refpect to the earth's axis, and the other pole in an oppofite direction. The direction in which this power acts, he takes to be the fame with that of the dipping needle; but we are weary of conjectures. The following experiment is the only one on which his hypothefis is founded: We took a foft fteel ramrod, which did not difcover the leaft fign of magnetism, and holding it in the direction of the dipping needle, Aruck it feveral smart blows with a hammer on one end; then lay ing it on a watch crystal it traverfed very well; that end which was held downward when ftruck, becoming a north pole, whether the ftroke was applied to the upper or the lower end. By turning the fouth end downwards and ftriking it afresh, the magnetism was destroyed or reverfed; and it was curious to observe how very nicely you must adjust the number and force of the ftrokes, precifely to deftroy the magnetifm before communicated, without giving it anew in a contrary direction. When we held the ramrod directly across the line of the dipping needle whilft it was ftruck with a hammer, it did not difcover any figns of magnetifm. But when held in any other direction, that end which approached nearest to the point which the lower end of the dipping tends to, always became the north pole. From all this, does it not feem very probable that during the concuffion of the ftroke, and whilft the magnetical particles of the rod were moft difengaged from the furrounding matter, the active power above mentioned feized them and arranged them properly, where, being confined, the rod afterwards remained magnetical ? This is undoubtedly a curious experiment, and we should be happy to find that it could be made ufe of for reducing the doctrine of magnetifm to a certain theory. Mr. Rittenhoufe's idea of the arrangement of his magnetical particles, though unfupported by demonftration or ocular proof, is nevertheless a curious conjecture, and may perhaps afford light for future travellers in the hitherto little known regions of magnetifm. A Defeription of the Grotto at Swatara. By the Rev. Peter Miller. This grotto is of confiderable extent and height: its roof is fupported by numerous ftalactitical pillars formed by the dropping of a calcareous water. It does not materially differ from others of a like kind. Our Author offers no conjectures concerning its formation; nor does he give any analysis of the petrifying water. Experiments and Obfervations upon what are commonly called the Sweet Springs. By J. Maddifon, Eq. This is a medicinal water in the county of Botetourt, much celebrated for its efficacy in relieving confumptive complaints, and other diforders proceeding from univerfal atony or debility. Mr. Maddison has, in this paper, recorded a few experiments which he made on this water. He has not given any analysis of it; but from the effects of various metallic folutions, he infers the component parts of the water to be a very fmall quantity of earth combined with an aeriform acid; the acid, however, predominates. Explanation of an optical Deception. By D. Rittenhouse. The optical deception here explained, is the apparent reversed furface of bodies when looked at through microscopes and telefcopes, viz. that fuch parts of the furface as are elevated, appear depreffed-and the contrary. This optical illufion is owing to the the inverfion of the image by the telescope while the light re mains the fame; Mr. R. in feveral experiments, obferved the deception to be removed by illuminating the object with a reflected (which is alfo an inverted) light. He likewife obferved, that upon taking out the glaffes, and looking through the open tube, that the object appeared in its unnatural or reverted state when illuminated with a reflected light; a tube is neceffary to confine the fight from other adjoining objects, which not being in the fame circumstances, would otherwife correct the imagination. Defcription of a remarkable Rock and CASCADE near the western Side of the Youghiogeny River, a Quarter of a Mile from Crawford's Ferry, and about Twelve Miles from Union in Fayette County, in the State of Pennsylvania. By Tho. Hutchins. This defcription is rather obfcure, and ought to have been illuftrated with a drawing. Any abridgment, we doubt, would be ftill more obfcure than the original. The cafcade, however, according to this account, certainly exhibits a most fingular, romantic, and grand appearance. An optical Problem propofed by Mr. Hopkinfon, and answered by Mr. Rittenhouse. Mr. Hopkinfon bolding near to his eye a filk handkerchief, tightly ftretched, and looking through it at a lamp which was at a confiderable diftance, obferved the threads of the handkerchief to be magnified to the fize of coarse wires; on moving the handkerchief flowly to the right and left he was surprized to find that the dark bars did not move at all, but remained permanent before the eye. Mr. Rittenhouse explains this appearance by a judicious and ingenious method: he confiders the crofs bars as an illufion, and not as the magnified threads; this illufion is caufed by the inflexion which the parallel rays coming from the lamp had fuffered in paffing the edges of the threads. His arguments are fupported by feveral experiments and illuftrations, which could not be understood without the figures. The MATHEMATICAL, ASTRONOMICAL, METEOROLO- ART. VIII. The History and Antiquities of the County Palatine of Durham. By William Hutchinfon, F. A. S. Vol. I. 4to. Subfcription for the whole 21. 25. Robinsons. 1785. THE HIS hiftory is written by Mr. Hutchinson, Author of the Excurfion to the Lakes, and View of Northumberland; who appears to have been particularly fortunate in obtaining a great variety of valuable materials for his work, having not only been indulged with leave to copy the public records of the fee, particularly the Doomfday book of the county of Durham (called Belden Bolden Buke), and Bishop Hatfield's Survey, but he has also been favoured with a great number of valuable communications, fuch as charters, pedigrees, monumental infcriptions, drawings, and manufcript collections, preferved in divers private libraries; and thefe are enumerated and acknowledged in a prefatory advertisement. Mr. Hutchinson opens his introduction with an eulogium on the labours of an hiftorian: 'The human genius,' fays he, knows not a nobler effort than that of collecting the various events of distant times, and placing them in fuch fucceffive order and arrangement as to exhibit a perfect delineation of the rife and progrefs of ftates, the civilization of mankind, and advances of fcience. By the labours of the hiftorian are tranfmitted the great viciffitudes which have attended on human affairs, and the knowledge of thofe principles which influenced the profperity as well as the decline of empires; from which affecting examples, wifdom forms her nobleft precepts. In fuch a review we become interested in the fate of the feveral perfonages who first attempted to release mankind from darkness and barbarifm, and our hearts participate the joy of those whose wisdom tamed the ferocity of favage habits, and cultivated the human mind in the school of fcience and the liberal arts. While through oral tradition alone, interefting events were communicated, history was dark and uncertain; affected by the fortunes of men, and fuffering mutilation by the fall of states, much obfcurity frequently enveloped the most important changes; for before the invention of letters, public monuments were the chief means of faving the greatest atchievements of nations, and the most wonderful acts of providential interpofition, from oblivion. To fuch we are obliged to refort, when we difcufs thofe diftant æras, in which letters did not prevail, or in the countries where they had not acceptation. The work of the hiftorian, in the first ages of literature, was laborious and unpleafant; much depending on the uncertain definition of emblematical images, and mysterious traditions; whilst a retrofpection through uncultivated ages, with the progrefs of ignorant and uncivilized nations, furnished difagreeable fcenes. It is fome happiness to us, that compaffionate angels have with-held the humiliating picture from our eyes.' Here we cannot help imagining that the conceit of these compaffionate angels may be an imitation of Sterne's recording angel, who with a tear blotted out the entry of the oath fworn by Uncle Toby; but, if fo, it is not a very happy one! Our Author then proceeds to give fhort accounts of the Druidical religion, the manners of the Brigantes, the acceffion of the Romans to that district, the introduction of Chriftianity, the laws by which the Brigantes were governed, the arrival of the Saxons, and the ftate of religion in Brigantia, the kingdoms of Bernicia and Northumberland, with a fucceffion of the kings, ending with Ofwald, and the foundation of the fee of Lindiffarne, in which the opulence and honour of the palatinate or REV. Feb. 1787. L Durham |