work are given both in English and French; and the figures being drawn by the. ingenious author after life, were afterwards etched by himself, and all the illu minated sets were coloured under his directions, and all touched up and finished by his own hand. The Inscription on a Roman Altar found near Stanhope in the Bishopric of Durham. Communicated to the Royal Society by the Rev. Thomas Birch, F. R. S. N° 486, p. 173. SILVANOINVICTOSACRVM CTETIVSVETVRIVSMICIA NVSPREFAIAESĘBOSIAA: NAEOBA PRAMEXIMIAE FORMAECAPTVMQVEM MVLTIANTECESSO RESEIVSPRAEDARI NONPOTVERVNTVSLP res ejus prædari non potuerunt Votum solven lubens posuit. Of an Extraordinary Fish, called in Russia Qual; and on the Stones called Crabs' Eyes. Communicated by Mr. Henry Baker, F. R.S. No 486, p. 174. As to the quab, which some report to be first a tadpole, then a frog, and at last a fish, it is very well known, says Dr. Mounsey, physician in Russia, to him; but with regard to such changes, he believes them to be entirely fabulous. He has indeed seen, in the chamber of rarities at Petersburg, this fish, preserved in spirits, under all these appearances; but was not permitted to take out any one of them, in order to remove the scruples he made; however, desiring as far as possible to come at the truth, he turned the bottle hastily on one side, to make the fish fall to the glass, which he thought they did with more seeming hardness than could be supposed in fishes; which induced him to conjecture, that they are pieces of art, the idea of which has been taken from the resemblance of the head of this fish to that of a frog. Whence he supposes they may be made of wax, and kept in this manner to amuse the world. If there be, he says, such a thing in nature, which he does not think probable, it must be peculiar to some one place, of which he has no knowledge. He has made inquiries about these imagined changes, of people of many nations, but could never learn any thing to the purpose. He has seen the fish itself in several countries, and found they spawned like other fishes, and grew in size, without the least similitude to what has been asserted. He adds further, that these fishes delight in very clear water, in rivers with stony or sandy bottoms, and are never found in standing lakes, or rivers passing through marshy or mossy grounds, where frogs chuse most to be. As to inquiries concerning the crabs' eyes, he expresses a surprise to find naturalists differ so much from each other, and yet not one of them he has ever seen giving any true account of the situation, formation, and casting of these concreted bodies. He therefore is so obliging to send the following description from his own observation and knowledge. Those concretions called crabs'-eyes, are found, he says, in the bodies of craw-fish. Each fish annually produces two, one on either side of the anterior and inferior part of the stomach, and each is generated about a point lying between the coats of it. The flat or concave side lies next the internal coat, which is very thin and clear, though strong and horny; the convex side is consequently outwards, and is immediately covered by the fleshy and softer coats of the stomach, whose fibres make impressions on its surface. Between these two membranes it grows by degrees lamellatim, and is supplied 'with petrifying juices discharged through the mouths of vessels or sudamina opening on the internal surface of the outer coat. The inner membrane, being horny, gives resistance only; hence the stones are concave on that side, and the first remarkable scale, on which all the others are formed, may be perceived in the centre, the brims or circumferences of many of the rest being very apparent. At the time when these stones are not to be found in the animal, there are little circular spots, somewhat opaque, and whiter than the rest of the stomach, to be perceived in their place; nearly opposite to which are tenacious mucilaginous substances, formed like little placentula, and called by some the glands of the brain; these are larger, and more perceptible, when the stones are wanting; but are not turned into stones by different degrees of induration, as some have imagined them to be. It is believed, he says, that they cast these stones with their shells, which they shed every spring, but he finds this is not the way of getting rid of them; for, a little before, or after the time of their casting their shell, the stones break through the internal or horny coat of the stomach, and being ground or broken by the three serrated teeth in it, become dissolved in the space of a few days, which makes it difficult to find them just at this time, and so gives ground to imagine they are cast with the shells. He says however, he has found several of them in the stomach partly consumed; and a further proof that they are so consumed is, he thinks, their being never discovered in rivers, though the fish themselves be in great plenty there; and in the shops it is observable, that many of these stones are of a brown hue; which is the case of such as have been already lodged in the cavity of the stomach, when the fish was taken. They likewise eat the old shells immediately after shedding them.* What the use of these stones to the creature is, he cannot positively determine, but supposes they may be designed to furnish new petrescent juices to its fluids; which may be also assisted by the old shells which they devour, the particles of which, as well as of the stones, are probably disposed of, according to their degree of purity, and properly deposited at the extremities of vessels, for the reproduction of their annually new crusty dress; which, he observes, does not greatly recommend the opinion that these stones have a dissolving quality, of service against the stone in the human kidneys or bladder. The Doctor has sent along with this particular account, specimens of the crawfish both boiled and raw, which differ little or nothing from those catched in our rivers here; in which it is assured the like concretions may be also found at a certain time of the year: he has likewise sent some of their stomachs dried, where the stones appear, situated in the manner above described between the 2 coats; and in one of them they are got through the internal coat into the stomach itself. He also sent several specimens of the beginning scales, or concretions, of different sizes, which he collected himself, in dissecting these creatures; several of the formed stones of his own taking out, some of a larger size, which were given him by a gentleman, who took them out of the craw-fish in the river Donne, and others still larger, which he chose from the apothecary of the army. These last were from Astracan: and he observes that the fish and stones are much the largest in the great rivers there, where there are fishers for craw-fish on account of the stones only; which they separate from the fish at different fisheries after different manners. At some they are beaten to pieces with wooden pestles; then washing away the flesh and shells, the stones are found remaining at the bottom of the vessel; at others they are laid in heaps till they rot; and then being washed, the stones are easily separated and gathered. All the apothecaries' shops throughout the whole Russian empire are furnished with them, and great quantities besides are exported. This seems to be a very particular and exact account of these productions, which are frequently prescribed in medicine. Their price, we find, is extremely low in the countries where they are gathered; and yet fictitious bodies, made of I have, says Mr. Baker, observed the same thing in the small fresh water shrimp; which I have kept in a glass with water throughout several of the periods of its casting its shell, which it does once in about 4 or 5 weeks. The water newt also eats its skin as soon as pulled off, if it be not taken away.-Orig. chalk, tobacco-pipe clay, or other such like materials, cast in moulds, so as to represent real crabs'-eyes, are often substituted instead of them. Brevis Historia Naturalis, sive de Vita, Genere, Moribusque Muris Alpini: Autore Jacobo Theodoro Klein, Reipubl. Gedanens. N° 486, p. 180. An account of the marmot, the natural history of which is now so well known, as to render even an abstract of this paper unnecessary. Concerning Electricity. By the Abbè Nollet, F. R. S. and of the Royal Academy of Sciences at Paris. Translated from the French, by T. Stack, M.D., F. R. S. N° 486, p. 187. When a vessel full of liquor, which runs out through a pipe, is electrified, the electrified jet or stream is thrown farther than usual, and is dispersed into several divergent rays, much in the same manner as the water poured out from a watering pot. Every body at first sight judges that the stream is accelerated, and that the electrified vessel will soon be empty. Being unwilling to rely on first appearances, M. N. resolved to ascertain the fact, by measuring the time, and the quantity of the liquor running out. And in order to know if the acceleration, supposing there was any, was uniform, during the whole time of the running out, he made use of vessels of different capacities, terminating in pipes of different bores, from 3 lines diameter to the smallest capillaries; and the following contain in gross the result of upwards of a hundred experiments, as it is not so easy a task to draw a safe conclusion, as may at first be imagined. 1. The electrified stream, though it divides, and carries the liquid farther, is neither accelerated nor retarded sensibly, when the pipe, through which it issues, is not less than a line in diameter. 2. Under this diameter, if the tube be wide enough to let the liquid run in a continued stream, the electricity accelerates it a little; but less than a person would believe, if he judged by the number of jets that are formed, and by the distance to which it shoots. 3. If the tube be a capillary one, from which the water ought naturally to flow only drop by drop; the electrified jet not only becomes continued and divided into several, but is also considerably accelerated; and the smaller the capillary tube is, the greater in proportion is this acceleration. 4. And so great is the effect of the electrical virtue, that it drives the liquid out of a very small capillary tube, through which it had not before the force to pass, and enables it to run out in cases where there would not otherwise have been any discharge. These last facts have served as a basis to his inquiries. He considered all organized bodies as assemblages of capillary tubes, filled with a fluid that tends to run through them, and often to issue out of them. In consequence of this idea, he imagined, that the electrical virtue might possibly communicate some 3 P VOL. IX. motion to the sap of vegetables, and also augment the insensible perspiration of animals. He began by some experiments, the result of which confirmed his notions. He electrified, for 4 or 5 hours together, fruits, green plants, and sponges dipped in water, which he had carefully weighed; and he found, that after this experiment, all these bodies were remarkably lighter than others of the same kind, weighed with them, both before and after the experiment, and kept in the same place and temper. He also electrified liquors of all sorts in open vessels; and he remarked, that the electrification augmented their evaporation, in some more, in others less, according to their differ natures. Therefore he took two garden-pots, filled with the same seeds; he kept them constantly in the sameplace, and took the same care of them, except that one of the two was elec-trified for 15 days running, for 2 or 3, and sometimes 4 hours a day. This pot always showed its seeds raised 2 or 3 days sooner than the other, also a greater. number of shoots, and those longer, in a given time: which shows that the electrical virtue helps to open and display the germs, and facilitates the growth of plants. He chose several pairs of animals of different kinds, cats, pigeons, chaffinches, sparrows, &c. and put them all into separate wooden cages, and then weighed them. He electrified one of each pair for five or six hours together: then weighed. them again. The cat was commonly 65 or 70 grains lighter than the other; the pigeon from 35 to 38 grains, the chaffinch and sparrow 6 or 7 gains: and in order to have nothing to charge on the difference that might arise from the temperament of the individual, he again repeated the same experiments, by electrifying that animal of each pair, which had not been electrified before; and notwithstanding some small varieties which happened, the electrified animal was constantly lighter in proportion than the other. Electricity therefore increases the insensible perspiration of animals: but in what proportion? Is it in the ratio of their bulks, or in that of their surfaces?: neither the one nor the other, strictly speaking, but in a ratio much more approaching to the latter than to the former. So that there is no room to apprehend that a human person electrified would lose near a 50th part of his weight, as it happened to one sort of bird; nor the 140th part, as to the pigeon, &c. All that he had been hitherto able to learn on this head, was, that a young man or woman, from 20 to 30, being electrified during 5 hours, lost several ounces of their weight, more than they were wont to lose, when they were not electrified. These last experiments are difficult to pursue with exactness; because the clothing, which cannot strictly be compared to the hair or feathers of animals, retains a good share of the perspired matter, and hinders us from forming a good judgment: of the whole effect of the electrical virtue. This forced electric perspiration is very naturally accounted for, if we consider, |