FRAME. SECOND ARTICLE. THE lungs are only one of the organs whose primary office is the purification of the blood. There are other elements, besides carbon and hydrogen, which have a tendency to accumulate in it to excess, yet the lungs are capable of removing none but them. Moreover, the lungs alone would be unable to carry off the whole excess even of these two substances. Hence a necessity for other excreting organs,—that is, for organs whose function is to secrete from the blood, and carry out of the system, whatever, either by its noxious qualities or its superabundant quantity, tends to dete been afforded to him in the earlier part of his journey, appears strange, but it is easily accounted for. When Ledyard obtained THE STRUCTURE AND FUNCTIONS OF THE HUMAN his passport and government protection the court was abroad, and occupied by amusements, and probably the Empress thought that by showing a trifling favour to an American, she would engage him in her service; and she was at that time extremely anxious to retain men of talent of any nation, and to spread abroad a good idea of her own administration; consequently, she considered it good policy to show favour to Ledyard, who was represented as a mere traveller, and from whom no harm was to be dreaded. The governor of Yakutsk must have known well that the views of Ledyard would, if realised, very much weaken the Russian power in Eastern Asia, and, at least, very much interfere with the establishments already made, and still extending, by which they then enjoyed a monopoly of the fur trade with the Northwestern American Indians. No wonder that he held Ledyard fast, till he could send home and get a ukase of banishment against our unfortunate traveller. Is it possible to conceive the feelings of a man, who, after triumphing over every difficulty, after penetrating from London to Yakutsk, one-half of the circumference of the globe, or nearly so, in the earnest pursuit of a purpose on which his mind was set; for the sake of which he had hazarded everything; for which he had suffered cold, hunger, and fatigue, when he found himself at length, after being trained on by flattering hopes, disappointed? Who that reads this narrative, and believes himself of sufficient spirit to have gone through what Ledyard suffered, would have borne up as he did? riorate the blood. Azote is the basis of animal structure, to which it is indeed peculiar, not entering at all into the composition of vegetables. It has been mentioned that a quantity of this gas is absorbed into the blood at every inspiration, and the need of some apparatus to limit the amount retained in the system is therefore obvious. This office is performed by the kidneys, two glandular bodies, situated one on each side of the spine, and possessing a very complicated structure. The importance of these organs may be estimated from He was turned adrift on the frontiers of Poland, without a the fact, that about a thousand ounces of blood circulate through penny, and commanded never to set foot again in Russia. He them every hour. The secretion of the kidneys consists of a large managed to raise five pounds on a draft on Sir Joseph Banks, quantity of fluid derived from the aqueous constituents of the and with these slender means contrived to reach London, where he arrived in the beginning of May, "disappointed, ragged, and blood, and holding in solution a great variety of substances,—that pennyless." He was received with great kindness by Sir Joseph peculiar to, and giving its name to the secretion, being urea, a Banks, who gave him a recommendation to the African Associa-highly animalised substance, the basis of which is azote. tion, who were then seeking for a traveller willing to explore the interior of Africa, and, if possible, discover the source of the Niger. Ledyard at once acceded to the proposition, and, on being asked when he should be ready to set out, promptly replied, "To-morrow morning." He left London on the 30th of June, and proceeded without accident to Cairo, but just as he was on the point of setting out with the caravan to Sennaar, he was attacked by illness, occasioned by exposure to the sun, and, notwithstanding the efforts of the best physicians at Cairo, he expired towards the end of November, 1788, in the thirty-eighth year of his age. THE POOR MAN'S MAY. SWEET MAY! they tell me thou art come : I cannot spare a single hour, God knows how hard I've worked this week, And see we have an empty board,— And thou art still the same sweet May I thought, oh! what a lovely world The hawthorn buds are come again, May sing the long day through. From Poems by John and Mary Saunders. The skin is an organ of great complexity and varied functions. It is composed of three layers,-the cuticle (or external skin), the rete mucosum (or mucous network), and the cutis (the true or internal skin). The cuticle is a thin, yet firm and strong, insensible membrane; the principal office of which is to diminish the force of external impressions; it also serves as a covering to the whole body, and confines and protects the soft tissues lying beneath. The rete mucosum connects the cuticle with the cutis, and is the seat of the colouring matter of the skin. The cutis is the chief part of the compound structure to which it belongs. It is composed of an infinite number of capillaries and nerves, of which, indeed, it wholly consists. These capillaries are the agents which perform the specific function of the skin,-the secretion and excretion of a large proportion of the superfluous hydrogen of the blood. Under ordinary circumstances, this element is removed by the skin in the form of an invisible vapour, which, when more abundantly evolved, condenses on the surface of the body. The former is called insensible, the latter sensible, perspiration. Along with these watery particles, and held in solution by them, a considerable number of other substances are conveyed out of the system. The quantity of matter excreted by the skin is exceedingly variable, depending chiefly on the degree of temperature to which the individual is exposed, which operates in this way by determining the distribution of the blood; great heat or exertion causing a large proportion of the entire mass of that fluid to flow into the cutaneous capillaries. In a state of health, insensible perspiration goes on uninterruptedly, and the average amount of this secretion in an adult has been estimated at from twenty to forty ounces in four-and-twenty hours. The liver has been already mentioned as assisting in digestion by means of its secretion, the bile. We have now to show its uses as a depurating organ. The liver is the only organ in the body (if we except the lungs) whose secretion is formed from venous blood the kidneys, the pancreas, the salivary glands, derive their respective products from arterial blood. Not so the liver. The veins of the digestive organs, instead of returning the blood directly to the heart, unite to form a large vein, the vena porta, which ramifies throughout the liver, and furnishes the materials from which the bile is eliminated. The principal constituents of bile are carbon and hydrogen, so that, by this process, the blood sent to the liver is freed from a large portion of those elements, and prepared for being more completely purified in the lungs. The liver is therefore subsidiary to the proper organs of respiration, from which it differs chiefly in the mode by which it decarbonizes the blood. Here may be mentioned the proper digestive function of the liver, by virtue of which it assists the stomach and other organs of digestion. Fluids, more especially fermented or spirituous liquors, are rapidly removed from the stomach by its capillary veins and absorbents, and are thus conveyed to the liver, to which, by similar means, are brought various products of the other organs, whose veins terminate there. Here these substances undergo a change, with the nature of which we are not acquainted, but which is doubtless a process of digestion, and are then transmitted with the blood into the heart and lungs. Hence it plainly appears that the liver is a digestive as well as an excreting and respiratory organ, being destined to operate upon substances on which the other digestive organs are not capable of acting. These various functions account for the great size of the liver, and its intimate connexion with the stomach, as well as for its extraordinary development in some of the lower classes of animals, as fishes and reptiles, whose respiratory system is simple and on a small scale. The principal functions of the intestines are, as we have seen, the separation of the nutritious from the excrementitious parts of the food, and the removal of the latter. These are not all, however: the mucous lining of the intestines is thickly studded with glands, which secrete a large quantity of fluid, consisting of effete particles of every kind entering into the composition of the body, and which is ejected along with the excrementitious portions of the bile and aliment. It frequently happens that more nutriment is formed than the system requires, and hence the blood becomes loaded with carbon and hydrogen. In such cases these elements combine, forming at, which is separated from the blood, and deposited, in various parts of the body, in the cellular tissue, by the capillary arteries of that tissue. By the combined operation of these organs-the lungs, the kidneys, the skin, the liver, the intestines, and by the cellular tissue, the blood is maintained in the proper condition for the carrying on of its function with regularity and perfection. To this end they are all indispensable; and, although their activity varies with varying circumstances, and one or more may, for a time, take scarcely any part in this grand process, their inactivity being compensated for by the greater vigour of others, yet health is not compatible with the continued cessation of the function of any one of them. It is observable that more than one organ is provided for each of the matters excreted from the blood; the object of which arrangement is to prevent the serious evils which would arise from the temporary derangement of an organ of this kind, were there none to supply its place. Hence all the organs just enumerated are closely implicated with one another, all being affected, to a greater or less extent, by the condition of each. The practical consequences of this fact are of the highest importance, and will hereafter be pointed out. The complicated and elaborate apparatus provided for the maintenance of organic life, especially as so much of it seems to produce no positive good, but merely to serve as preventives of evil, may, at first sight, appear to betoken imperfection in the original constitution of the animal economy. The human frame is, doubtless, a structure far from simple, yet no part of it is superfluous. On the contrary, we find in it a wonderful economy of instruments; various and apparently independent effects being produced by one set of means and agencies, in a way which never fails to excite our admiration, by the display of profound wisdom and perfect control over the materials employed which such manifestations indicate. Some remarkable instances of this kind next claim our attention. One of the essential characteristics of life is a temperature more or less elevated, independent of that of the media by which living beings are surrounded. A certain degree of heat, varying in different classes of organised bodies, is indispensable to the continuance of life, every deviation from it being either a cause or a consequence of disease, and, when it reaches beyond a given point, destructive of life. The production and regulation of this temperature are effected by the organs of organic life: so long as they are healthy and vigorous, the exact degree of heat required is kept up in the animal economy, in spite of the influence of external agents. The sources of terrestrial heat are both numerous and diversified, yet" the discoveries of chemists have referred most of these to the general head of chemical combination. Thus, fire, or the combustion of inflammable bodies, is nothing more than a violent chemical action attending the combination of their ingredients with the oxygen of the air." * This brief quotation contains the explanation of the generation of animal heat. Carbon, an inflammable substance, the basis of coal, wood, &c., is continually entering into the blood, and as constantly being removed from it, by combining with oxygen. Here, then, are all the conditions necessary to the production of heat. Thus, the same process that purifies the blood also generates the vital heat, equally indispensable with the blood to organized existence: the accumulation of carbon in the blood is, therefore, not an evil,—not a circumstance indicative of imperfection,—but one absolutely essential to life, and a mark of beneficent design. So far, the theory of animal heat is free from difficulty, but in other respects it is still, to some extent, unsettled,—that theory which appears most satisfactorily to account for all the observed phenomena involving several points in physiology which are yet matters of dispute. On this account, and as the subject does not bear directly on the object we have in view, we shall not enter upon it here, further than to quote the conclusion at which Dr. S. Smith arrives respecting the question. "The result of the whole is the complete establishment of the fact that the production of heat in the animal body is a chemical operation dependent on the combination of oxygen with carbon in the capillary arteries of the system, —that is, it is the result of the burning of charcoal at every point of the body." Numerous experiments have decisively proved that this chemical process is greatly aided by the vital functions of the nervous system, which are, indeed, essential to its continuance. In what mode it is so, however, we are still ignorant: whether, as some suppose, by the electrical properties which they attribute to the nervous centres, or by the direct generation of heat, being undetermined. One of the best ascertained laws of heat is its tendency to equal distribution. Now, since the media in which animals exist are liable to great and sudden variations of temperature, it might be supposed that the heat of animals would undergo corresponding changes. Such, however, is not the case. The natural heat of man remains, with little variation, the same in the hottest regions * Sir J. Herschell's Discourse on the Study of Natural Philosophy, p. 312. of the tropics and in the midst of the ice-bound oceans around the poles: nay, even when exposed to artificially created temperatures, higher than any that are met with in the warmest climates. The processes by which this is accomplished, and which come under the denomination of those which protect the animal economy from external agents, are next to be considered. It has been proved by experiment that the quantity of oxygen consumed by man diminishes in proportion as the temperature of the atmosphere rises: for, as the air expands in the same proportion, fewer particles of oxygen enter the lungs, and con. sequently less carbonic acid is formed; the excess of carbon not removed by respiration being, in such cases, secreted by the liver, as already explained. Here, then, is a direct provision for counteracting the effect of too high an external temperature, by limiting the amount of animal heat generated. peculiar class of glands, termed conglobate. Collectively, the office of those organs is, as the name denotes, to take up the various particles that come in contact with their extremities, and to convey them into the blood. The thoracic duct is the common termination of the whole absorbent system. The special functions of the lacteals have been already stated. The lymphatics are exceedingly minute vessels, closely resembling the lacteals in structure; they penetrate every part of the body, and are probably the sources of the absorbent power of the skin, and of the surface of several internal organs, by means of which substances placed upon them are speedily removed into the circulation. But the characteristic office of the lymphatics is, in conjunction with the capillaries, to build up and keep in repair the organs of the body. Pervading every tissue in countless numbers, they remove the worn-out particles from their various combinations, and thus prepare the receptacles in which the capillary arteries deposit the newly-formed particles, and hence they have been aptly termed the architects of the animal structure. On them is greatly depen dent the condition of the entire frame. If they are too active, the body becomes emaciated and weakened; if insufficiently so, deposition proceeds too rapidly, and a plethoric state of the system is induced, and, at the same time, noxious particles are suffered to remain and accumulate. The influence of heat upon the distribution of the blood has been before alluded to, and this is another means for effecting the purpose under consideration. When an animal is removed into a higher temperature, the action of the heart is increased, the circulation is accelerated, and thus a larger quantity of blood is sent to the lungs and skin. In these organs, being acted upon by the heat, a portion of the watery constituents of the blood is converted into vapour and poured out on their surfaces, whence it is carried off by the surrounding air. Now, the change of a substance from a state Sensibility is generally regarded as an essential attribute of of less to one of greater rarity occasions the absorption of caloric; nerves. This, however, is an erroneous notion. The nervous the vapour or steam arising from boiling water, for instance, pre-system is composed of two parts, the sentient, of which the brain vents it ever rising above a certain temperature, whatever degree of heat it may be subjected to. In like manner, evaporation from animals lowers their temperature by absorbing and carrying off the superabundant heat; and so effectual is this process that persons may remain for considerable periods in an atmosphere many degrees hotter than boiling water, without injury and almost without inconvenience! In such circumstances the loss of substance is, of course, very great; men engaged in gas-works, &c. frequently lose four or five pounds in weight in a short time. Man is exposed to degrees of temperature as far below his own natural heat as those just referred to are above it. In the polar regions the temperature of the atmosphere is sometimes as low as forty or fifty degrees below zero, that is, 140 degrees lower than that of man, which latter is nevertheless maintained in spite of the constant radiation of heat from his body. It must be noted, however, that man could not long exist under such circumstances but for the assistance of art; he clothes himself in the thick furs with which the lower animals destined to inhabit such localities, are provided, and which, being bad conductors of heat, diminish greatly the loss of caloric. The natural provisions for enabling man to resist the influence of intense cold are principally, increased consumption of oxygen and production of carbonic acid, and diminution of evaporation. Cold contracts the capillaries on the surfaces of the body, and thus lessens the quantity of blood contained in them, and thereby, and by the direct influence of low temperature, evaporation is, to a great extent, prevented. It may be observed, also, that the food of animals living in cold climates is almost exclusively animal, which contains a larger proportion than vegetables of carbon and hydrogen—at least, of those elements in a state fit to enter into and form part of the body, which thus receives a more abundant supply of combustible matter than it would if vegetables were the chief articles of food. Before concluding this exposition of the laws of organic life, we must briefly describe two sets of organs which exert a general influence upon that as well as upon the animal life, namely, the absorbent system and the organic nerves. and spinal cord are the central masses, and the organic, which is organic life as is necessary for our purpose.. The absorbent system consists of lacteals, lymphatics, and a compendium. WELLS CATHEDRAL. It is very remarkable that Wells Cathedral was finished in 1242, two years after the birth of Cimabue, the restorer of painting in Italy; and the work was going on at the same time that Nicolo Pisano, the Italian restorer of sculpture, exercised the art in his own country: it was also finished fortysix years before the Cathedral of Amiens, and thirty-six years before the Cathedral of Orvieto was begun; and it seems to be the first specimen of such magnificent and varied sculpture, united in a series of sacred history, that is to be found in Western Europe.-Flaxman's Lectures on Sculpture. FAST DRIVING. "Coachman," said an outside passenger to one who was driving at a furious rate over one of the most mountainous roads in the north of England, "have you no consideration for our lives and limbs?"-" What are your lives and limbs to me," was the reply; "I am behind my time!"— New York Mirror. IPHIGENIA IN AULIS. Rent on the earth her maiden veil she throws, That emulates the rose; And on the sad attendants rolling The trembling lustre of her dewy eyes, Their grief-impassioned souls controlling, That ennobled, modest grace, Which the mimic pencil tries In the imag'd form to trace, The breathing picture shows; And as, amidst his festal pleasures, Her father oft rejoiced to hear Her voice in soft mellifluous measures So now in act to speak the virgin stands; She heard her father's dread commands And for her country's good, With patient, meek submissive mind Pour'd out the rich stream of her blood. A DUTCH ASSEMBLY. Potter's Eschylus. An unfortunate Irishman known by the name of Lord Kerry, being the other night at one of the Dutch assemblies, and quite overcome with its stupidity, yawned so terribly that he fairly dislocated his jaw. It was immediately set again; but he has suffered much from the accident, and is still confined by it to his bed. He is a man upwards of fifty, and consequently, must have been frequently ennuied before. But such peculiar ennui was more than he had bargained for, or had power to resist. You may think this is a made anecdote, but I assure you I have told you the plain matter of fact.-Letter of M. G. Lewis. FIRST INSTANCE OF BRIBERY IN THE HOUSE OF COMMONS. 1571 A. R. 13-May 10. Thomas Long, "a very simple man and unfit" to serve, is questioned how he came to be elected. He confesses that he gave the Mayor of Westbury and another four pounds for his place in Parliament. They are ordered to repay this sum, to appear to answer such things as should be objected against them in that house, and a fine of twenty pounds is to be assessed on the corporation and inhabitants of Westbury, for their scandalous a ttempt. - Parry's Parliaments and Councils of England. DISPROPORTIONED PUNISHMENTS. Whenever the offence inspires less horror than the punishment, the rigour of the penal law is obliged to give way to the common feelings of mankind.-Gibbon. A NEGRO CHILD'S BURIAL. A friend, who had resided some time in Brazil, told an anecdote, which was extremely pleasing to me, on account of the distinct and animating faith it implied. When walking on the beach, he overtook a negro woman, carrying a large tray upon her head. Thinking she had fruit or flowers to sell, he called to her to stop. On being asked what she had in her tray, she lowered the burthen upon the sand, and gently uncovered it. It was a dead negro babe, covered with a neat white robe, with a garland around its head, and a bunch of flowers in the little hands, that lay clasped upon its bosom. "Is this your child?" asked my friend. "It was mine a few days ago," she said; "but it is the Madonna's now, I am carrying it to the church to be buried. It is a little angel now." "How beautifully you have laid it out!" said the traveller. "Ah!" replied the negro," that is nothing compared to the beautiful bright wings with which it is flying through heaven !"-The Mother's Book. THE TRIGGER FISH. We were boarded by some little canoes, hollowed from logs, when fully ten miles from the shore; nor did the poor fishermen in these frail vessels appear to feel any concern at the distance. From one of these boats we obtained some fish of an oval shape, of one to two pounds in weight and a deep blue colour, spotted all over with white. Sailors call them "trigger" fish because their large back-fin cannot be pressed backward by a strong effort, but is levelled by the slightest touch on a smaller fin, planted a little below it.-Voyage of the Brig Himmaleh. ANECDOTE OF KING JAMES I. In the midst of the Spanish match, the king, who was at Theobalds, was much discomposed by missing some important papers which he had received respecting it. On recollection, he was persuaded that he had intrusted them to his old servant Gib, a Scotchman and gentleman of his bed-chamber. Gib on being called declared, humbly but firmly, that no such papers had ever been given to his care; on which the king, transported with rage, after much reviling, kicked him as he kneeled before him. "Sir," exclaimed Gib, instantly rising, "I have served you from my youth and you never found me unfaithful; I have not deserved this from you, nor can I live longer with you under this disgrace: fare ye well sir, I will never see your face more:" and he instantly took horse for London. No sooner was the circumstance known in the palace, than the papers were brought to the king by Endymion Porter, to whom he had given them. He asked for Gib, and being told he was gone, ordered them to post after him and bring him back; vowing that he would neither eat, drink, nor sleep till he saw him. And when he at length beheld him entering his chamber, he kneeled down and very earnestly begged his pardon; nor would he rise from this humble pos ture till he had in a manner compelled the confused and astonished Gib to pronounce the words of absolution.-Miss Aikin's Memoirs of James I. THE SONG OF THE LARK. The Lark proclaimed the joys of the coming year, and awakened endless hopes, while she soared circling higher and higher, till, at length, her song was like the soft whisper of an angel holding converse with the spring, under the blue arch of heaven-The Story without an End. WHO NEVER COMMEND BUT WITH A "BUT." I knew a man who never heard any one praised but he damped the praise. He did praise, occasionally, but then it was to mortify the listener. If the listener praised, in turn, he would immediately change sides, and begin to censure the very person he had before eulogised. He went to church every Sunday; read the prayers audibly; sung with the clerk; would cry like a child in misfortune; and, in the course of an hour, sing a song to drive his care away. He never commended but with a "BUT." With him Naaman was an honourable man, and a mighty man of valour-BUT--he was a leper!-Bucke's Book of Human Character. CHEAP. A tradesman in the country tendered an account in which was the following item; and, considering the job, his charge was certainly moderate :-"To hanging wickets and myself, seven hours, five shillings and sixpence."-New York Mirror. THE HONEY-BIRD. In the country of the Amakasa wild honey is found plentifully, and the natives very frequently avail themselves of the assistance of the honey-bird, or bee-cuckoo, (Cuculus Indicator), in searching for it. This bird, which is of a cinereous colour, and somewhat larger than the common sparrow, is well known in South Africa for its extraordinary faculty of discovering the hives or nests of the wild bees, which in that country are constructed either in hollow trees, in crevices of the rocks, or in holes in the ground. Being extremely fond of honey, and of the bees'-eggs, or larvæ, and at the same time unable, without assistance, to obtain access to the bee-hives, nature has supplied the Indicator with the singular instinct of calling to its aid certain other animals, and especially man himself, to enable it to attain its object. This is a fact long ago established on the authority of Sparrman, Vaillant, and other scientific travellers in Southern Africa. With the habits of this curious bird I was myself acquainted during my residence in the interior of the Cape colony, and have often partaken of wild honey procured by its guidance. It usually sits in a tree by the way-side, and, when any pas. senger approaches, greets him with its peculiar cry of cherr-a-cherr! cherra-cherr! If he shows any disposition to attend to its call, it flies on before him in short flights, from tree to tree, till it leads him to the spot where it knows a bee hive to be concealed. It then sits still and silent till he has extracted the honeycomb, of which it expects a portion as its share of the spoil; and this share the natives who profit by its guidance never fail to leave it. Some of the native Hottentots assert, also, that to obtain access to the hives in hollow trees, the honey-bird sometimes calls to its aid the woodpecker, a bird which finds in the larvæ, or young bees, a treat as enticing to its taste as the honey is to that of its ingenious associate.-African Sketches, by Thomas Pringle. A FRIEND IN NEED IS A FRIEND INDEED. WHEN Drury-lane Theatre was burnt, Bannister the comedian was amongst the losers of property, as well as of situation. His wife was a relation of Rundle the goldsmith, who sent Bannister the following letter: "Ludgate-hill, 27 Feb. 1809. "Dear Sir:-I have great pleasure in inclosing you a bank-note for 5001, which I hope you will do me the favour to accept, în consideration of the loss you may sustain from the late serious change in the concern. "I remain, dear sir, with the greatest regard for your welfare, your friend and humble servant, "PHILIP RUNDLE. "I presume there will be a subscription opened for those in distress." Bannister's Memoirs. London: WILLIAM SMITH, 113, Fleet Street. Edinburgh: FRASER & Co. Dublin: CURRY & Co.-Printed by Bradbury & Evans, Whitefriars. THE No. XIX. PUBLISHED BY WILLIAM SMITH, 113, FLEET STREET. ANIMAL MAGNETISM. No. V. SATURDAY, MAY 11, 1839. CONCLUDING VIEW OF THE NATURE OF ANIMAL MAGNETISM. "You are aware," continued M. de L., "that, besides light and heat, there are two other imponderable and prodigiously subtle bodies, which lend their concurrent aid in governing the universe of matter and its changes,—so far, at least, as regards the planet we inhabit: I mean electricity and magnetism. Many philosophers regard these four substances or elements as imparting condition to matter, rather than as forming any part of matter itself. But, imponderable though they be, they nevertheless occupy space, and two of them, at least, offer resistance; facts evident to the physical senses of organised beings: they may, therefore, justly be considered matter. I accordingly term them 'bodies.' By their nature, light, heat, electricity, and magnetism, are fluids, but of more refined and penetrating action than the most subtle and expansive of the elastic fluids called 'gases.' The necessity of light, and its chemical action upon matter, needs not now to be discussed, any more than the properties of heat, by which all nature is maintained in form and life. But if light be necessary to bring about many changes in matter inorganic, and, in most cases, indispensable to the very life of organised matter; and if heat be indispensable to impart form and bulk to the material world; electricity and magnetism are equally so to direct the general polarity of matter,-a condition necessary, not only to marshal it to the laws of gravitation and motion, but to excite those changes arising from what is termed 'chemical action.' Besides the general polarity of the world, its component parts, even, no doubt, to its ultimate atoms, have individual polarity, governed by the same laws. This is, however, foreign to the subject now under our consideration, but may form a topic on some future occasion. "Thus, then, electricity and magnetism have an action upon matter, from which it renders them as inseparable as light and heat. Volta having discovered galvanism to be identical with electricity, some other philosopher may hereafter show that magnetism is only a modification of the electric principle; that the polarity of matter, and the chemical arrangements dependent upon it, are directed by one fluid only, and not by two; that, in short, the whole material universe is under the control of a general directing or governing principle, which may be called 'electricity,' or 'magnetism,' or by some more appropriate name." "That there is a very close connexion between electricity and magnetism is evident from the discoveries of the Danish philosopher, Oersted, in 1819. His experiments have been since followed out and illustrated by Ampère, De la Rive, Arago, your own Davy, and many other illustrious men. These discoveries show most satisfactorily that the action of magnetism is under the The word electricity is derived from the Greek word λEKTрov (electron), which signifies amber. This name was given from the circumstance that the discoverer of electricity, Thales of Miletus, found it to arise from the friction of amber. Magnetism comes from the Latin word "magnes," which means the lodestone, or stone that attracts iron.-" Magnes ad se ferrum allicit et trahit."-Cic. VOL. I. [PRICE TWOPENCE. direct influence of electricity. They further justify the wellgrounded supposition that the immediate cause of the variation in the magnetic needle, which so materially affects navigation, is the action of electricity under polar connexion. I will endeavour to explain this to you more clearly. "The two poles of a voltaic apparatus,—the positive pole, as you know, yielding vitreous, the negative yielding resinous, electricity, are connected by a wire of platinum, gold, or iron. This wire, being rectilinear almost from end to end, is directed in the exact line of the magnetic meridian. If a magnetic needle, properly suspended, and attached to a diagram representing the points of the mariner's compass, be placed with its centre immediately under this connecting wire, the pole of the needle nearest to the negative electric pole will decline towards the WEST; but, if the needle be placed in the same situation above the connecting wire, its declination will be towards the EAST. In neither case, however, does the declination exceed an angle of ninety degrees. Some day, I will show you two or three singular experiments connected with this fact, which very materially strengthen the evidence it offers of so close a connexion between electricity and magnetism, that identity may almost be inferred. "There is another point which I must notice. If light, heat, electricity, and magnetism, be matter, though imponderable, do they enter into chemical union with matter? My opinion is, that they do. Heat gives form and bulk to all bodies, by lying between their ultimate atoms, which it keeps asunder to the utmost extent permitted by the power of cohesion peculiar to the separate qualities of each body. The different bulks and specific qualities of bodies depend, therefore, upon the interposition of heat, the substances which contain the greatest quantity being the most porous, and therefore the lightest, because their constituent atoms are the farthest asunder. But the heat which regulates this specific gravity, and that also which maintains matter in its several conditions of solid, liquid, and vapour or gas;-that is to say, the constituent heat of matter-loses by its combination, by its very quality of constituent heat, its distinctive property of affording sensible warmth. Constituent heat does not affect the most delicate thermometer. But when this kind of heat is separated from the body to which it is united, it immediately resumes its power of affording warmth, and will act upon the mercury in the thermometer. For example: steam and boiling water are of the same precise temperature-100° centigrade *; but steam absorbs, beyond this, 555.8° † of constituent heat, although its temperature never exceeds 100°. Did it not absorb this heat, it would remain water at the temperature of steam. When this latter is re-condensed to water, it parts with its constituent heat, which, on being liberated, recovers the property it had lost, and sensibly affects the surrounding media. Again: ice, and water just melted from ice, absorbed 77.812°§ of heat, which has become insensible, but withshow the same temperature, that of zero; but the water has out which the water at zero would have remained ice. This latter 2120 Fahrenheit. 32° Fahrenheit. Bradbury and Evans, Printers, Whitefriars. +1000° measured by Fahrenheit's scale. § 1400 Fahrenheit's scale. U |