that they were shocked by laying one hand on him. I myself have taken hold of the largest with one hand often, without ever receiving a shock; but I never touched it with both hands, at a little distance asunder, without feeling a smart shock. I' have often remarked, that when it is taken hold of with one hand, and the other hand is put into the water over its body, without touch ing it, the person received a smart shock; and I have observed the same effect follow, when a number joined hands, and the person at one extremity of the circle took hold of, or touched the fish, and the person at the other extremity put his hand into the water, over the body of the fish. The shock was communicated through the whole circle, as smartly as if both the extreme persons had touched the fish. In this it seems to differ widely from the torpedo, or else we are much misinformed of the manner in which the benumbing effect of that fish is communicated. The shock which our Surinam fish gives, seems to be wholly electrial; and all the Phænomena or proprieties of it exactly resemble those of the electric aura of our atmosphere when collected, as far as they are discoverable from the` several trials made on this fish. This stroke is communicated by the same conductors, and intercepted by the interposition of the same original electrics, or electrics per se as they used to be called. The keeper of this fish informs me, that he catch ed them in Surinam river, a great way up, beyond where the salt water reaches; and that they are a freshwater fish only. He says, that they are eaten, and by some people esteemed a great delicacy. They live on fish, worms, or any animal food, if it is cut small, so that they can swallow it. When small live fishes are thrown into the water, they first give them a shock, which kills or so stupifies them, that they can swallow them easily, and without any trouble. If one of these small fishes after it is shocked, and to all appearance dead, be taken out of the vessel where the electrical fish is, and put into fresh water, it will soon revive again. If a larger fish than they can swallow bethrown into the water, at a time that they are hungry, they give him some smart shocks, till he is apparently dead, and then they try to swallow or suck him in; but, after several attempts, finding he is too large, they quit him. Upon the most careful inspection of such fish, I could never see any mark of teeth, or the least wound or scratch on them. When the electrical fish are hungry, they are pretty keen after their food; but they are scon satisfied, not being able to contain much at one time. An electrical fish of three feet and upwards in length cannot swallow a small fish above three or at most three inches and a half long. Since I wrote the above description and remarks, I have had Mr. Bancroft's Essay on the Natural History of Guiana put into my hands, in which I find an account of this animal; but, as I think that he has not been very particular in the description of it, I resolved still to send you the above account, that you might judge for yourself. I observed, that his account or description and mine dif. fer in several things; and amongst others, where he says, that those fish were usually about three fect in length; but the one, of which I have sent a slight description, was three three feet eight inches. This small variation might indeed have happened without any error; but I am told, that some of them have been seen in Surinam river upwards of twenty feet long, whose stroke or shock proved instant death to any person that unluckily received it. I shall be on the watch to procure a more accurate knowledge of, and acquaintance with, this animal; and if I can learn any thing farther about it, you may depend on my communicating it. Some Account of a Tree growing in Spain, called the Algarroba, Garofero, Carrobe, or Locust-Tree, which produces vast Quantities of Fruit, often eaten by Man, and constantly by the Cattle of that Country, to whom it is Physic, as well as Food. the leaves are of a dark green, ten on a twig, five on each side; the fruit exactly resembles kidneybeans, and is an inch broad, and nine or ten inches long; they issue in clusters from the branches and body of the tree in a very singular manner; these pods are thick, mealy, and of a sweetish taste: when dry they are given to horses and cattle as provender. These trees are only found in this province, and those of Murcia, Granada, and Andalusia *. I observed at Alicant, in the garden of el Senor Barnabeau, a very large garofero, or carrobetree; it produces annually one hundred and thirty arrobes of fruit (each arrobe is twenty-six pounds), which are sold for seventy dollars, about eleven pound fourteen shillings. This tree may serve as companion to the great orange-tree, which From Travels through Spain, by Mr. Wood of Oporto shewed me in Richard Twiss, Esq; THIS is an eversually from one to two feet in diameter; the garden of his country-house, * Inthe second volume of Mr. James's History of Gibralter, the author, describing the plains of Tetuan, says, "the next remarkable sort of wood is "the alcarobe, a tree of great curiosity, and merits much notice; the alcarobe bears a pod in quantity and likeness much resembling the English bean; "the inner substance thereof is sweet, and lodgeth hard small kernels. This fruit is eaten by the Moors of inferior condition, and by all at the feast Ashorah; but it is chiefly preserved for their horses, to whom it is both "physic and repast; for the fruit of the alcarobe hath two excellent proper"ties, to drench and make their horses fát. "Some have called the fruit locusta, and supposed it was the Baptist's "food in the wilderness, &c. &c. There is a great probability that the fruit of the alcarobe is the same with the Prodigal's ceratia, or husks, "for it doth excellently accord with their description." Mr. Armstrong, in his history of Minorca, p. 195, likewise mentions the opinion in regard to its having been the food of St. John, but he adds wild honey to it. Miller calls it ceratonia, carouge, and St, John's bread. A Description A Description of a newly discovered Sensitive Plant, called Dionæa Muscipula, or Venus's Fly-trap. EY VERY one skilled in Natural History, 'knows that the Mimosa, or sensitive plants, close at their leaves, and bend their joints upon the least touch: and this has astonished us; but no end or design of nature has yet appeared to us from these surprising motions: they soon recover themselves again, and their leaves are expanded as before. But the plant, which we are now going to describe, shews that nature may have some view towards its nourishment, in forming the upper joint of its leaf like a machine to catch food; upon the middle of this lies the bait for the unhappy insect that becomes its prey. Many minute red glands that cover its inner surface, and which perhaps discharge sweet liquor, tempt the poor animal to taste them; and, the instant these tender parts are irritated by its feet, the two lobes rise up, grasp it fast, lock the rows of spines together, and squeeze it to death. And further, lest the strong efforts of life in the creature thus taken, should serve to disengage it, three small erect spines are fixed near the middle of each lobe among the glands, that effectually put an end to all its struggles. Nor do the lobes ever open again, while the dead animal continues there. But it is nevertheless certain, that the plant cannot distinguish an animal from a vegetable or mineral substance; for, if we introduce a straw or a pin between the lobes, it will grasp it full as fast as if it was an insect. A short time since, Mr. Peter Collinson sent Mr. ElHis a dried specimen of this curious plant, which he had received from Mr. John Bartram, of Philadelphia, Botanist to the King. The flower of this specimen, Dr. Solander dissected, found it to be a new genus; but, not suspecting then the extraordi nary sensitive power of its leaves, as they were withered and contracted, he concluded they approached near to the Drosera or Rosa Solis, to which they have been supposeď by many persons since to have a great affinity, as the leaves of the most common English species of the Rosa Solis are round, concave, beset with small hairs, and full of red viscid glands. But we are indebted to Mr. William Young, a native of Philadelphia, (to whom likewise the royal favour has been extended for his encouragement in his botanical researches in Ame rica) for the introduction of this curious plant alive, and in considerable quantities. He informs me, that they grow in shady wet places, and flower in July and August; that the largest leaves which he has seen were about three inches long, and an inch and a half across the lobes, and observes, that the glands of those that were exposed to the sun were of a beautiful red colour, but those in the shade were pale, and inclining to green. It is now likely to become an inhabitant of the curious gardens in this country, and merits the attention of the ingenious. The botanical characters of the Genus Dionæa, according to the Linnæan sexual system, where it came under the class of Decandria Monogynia, are these: The The Calix or flower cup, consists of five small, equal, erect leaves of a concave oval form, pointed at the top. The Corolla, or flower, has five concave petals of an oblong invert ed oval form, blunt at the top; which curls in at each side, and is streaked from the bottom upwards with seven transparent lines, The Stamina, or Chives, have ten equal filaments; shorter than the petals; and their tops, which contain the male dust, are roundish, This dust, or farina fæcundans, when highly magnified, appears like a tricoccous fruit. The Pistil, or female organ, has a roundish germen, or embryo seedvessel, placed above the receptacle of the flower; this is a little de pressed and ribbed like a melon. The stile is of a threadlike form, something shorter than the fila ments. The stigma or top of the stile is open, and fringed round the margin. The Pericarpium, or seed-vessel, is a gibbous capsule, with one cell or apartment. The Seeds are many, very small, of an oval shape, sitting on the bottom of the capsule. This plant is herbaceous, and grows in the swamps of North-Carolina, near the confines of SouthCarolina, about the latitude of 35 degrees north, where the winters are short, and the summers very hot. The roots are squamous, sending forth but few fibres, like those of some bulbs; and are perennial. The leaves are many, inclining to bend downwards, and are placed in a circular order; they are jointed and succulent; the lower joint, which is a kind of stalk, is flat, longish, two-edged, and inclining to heart-shaped. Is some varieties they are serrated on the edges near the top. The upper joint consists of two lobes; each lobe is of a semi-oval form, with their margins furnished with stiff hairs like eye-brows, which embrace or lock in each other, when they close; this they do, when they are inwardly irritated. The upper surfaces of these lobes are covered with small red glands, each of which appears when highly magnified, like a compressed Arbutus berry. Among the glands about the middle of each lobe are three very small erect spines. When the lobes inclose any substance, they never open again, while it conti nues there. If it can be shoved out, so as not to strain the lobes, they expand again; but, if force is used to open them, so strong has nature formed the spring of their fibres, that one of the lobes gene rally snaps off rather than yield. The stalk is about six inches high, round, smooth, and without leaves, ending in a spike of flow ers. The flowers are milk-white, and stand on foot stalks, at the bottom of each of which is a little painted bractea or flower-leaf. As to the culture of it, the soil it grows in (as appears from what comes about the roots of the plants, when they are brought over) is á black light mould, intermixed with white sand, such as is usually found in our moorish heaths. Being a swamp plant, a north cast aspect will be the properest situation at first to plant it in, to keep it from the direct rays of the meridian sun; and, in winter, till we are acquainted with what cold weather C ог weather it can endure, it will be necessary to shelter it with a bell glass, such as is used for melons; which should be covered with straw a mat in hard frosts: by this method several plants were preserved last winter in a very vigorous state. Its sensitive quality will be found in proportion to the heat of the weather, as well as the vigour of the plant. Our summers are not warm enough to ripen the seed: or possibly we are not yet sufficiently acquainted with the culture of this plant. In order to try further experi ments to show the sensitive powers of this plant, some of them may be planted in pots of light moorish earth, and placed in pans of water in an airy stove in summer, where the heat of such a situation, being like that of its native country, will make it surprizingly active. A Description of a petrified Stratum, formed from the Waters of Matlock, in Derbyshire. By Matthew Dobson, M. D. Communicated by Dr. Fothergill. • From the Philosophical Transactions. URING a short stay at Matlock, this summer, I made some observations on the petrifying quality of the waters, and examined a very singular Stratum, which has been formed in their course. This Stratum I found about 500 yards in length; in several places, near 100 yards in breadth; and, where thickest, from 3 to 4 yards in depth. The manner, in which this body of stone has been produced, is easily ascertained. Within the memory of some per sons now alive, the waters of Matlock were not appropriated to the purposes either of bathing or drinking. They issued from near the bottom of the hill, which lies to the west, immediately behind the present houses, and ran at random, down a declivity of about 100 yards, to the river Derwent. In their course, they formed large petrified masses, intermingled with great quantities of petrified moss, nuts, leaves, acorns, pieces of wood, and even trunks of trees. The waters were thus constantly raising cbstacles to their own progress, and were frequently therefore forced into new channels; só as, by degrees, to be extended over a surface of at least 500 yards in length. And, by being repeatedly returned into the same channels, a Stratum, of considerable thickness, has been formed. On examining this Stratum, some parts are discovered to be extremely hard, and others so soft, as easily to be cut. The soft parts, however, on exposure to the air, become as hard as flint; and on being struck, sound like metal. The reason of this difference in the hardness of different parts, appears to be this: as the waters frequently changed their channels, and repeatedly likewise returned again to the same channels, if, in the intervals, there were any parts considerably raised, and consequently longer before they were covered with fresh incrustations, thest, from a longer exposure to the air, would acquire a greater degree of hardness. Whole houses, in the neighbourhood, are built of this stone, which they find more durable, than any other |