MISCELLANEA. ON THE INFLUENCE OF THE SOLAR RAYS IN PRODUCING CHEMICAL OR MOLECULAR CHANGE. BY MR. HUNT. MR. HUNT, at the sitting of the Royal Institution, Feb. 13, having briefly sketched the progress of philosophical inquiry into the chemical influence of the solar ray from the original researches of Daguerre and Talbot, proceeded to develop his own views in regard to the prismatic spectrum. Hastily noticing the well-known phenomena of light and heat as connected with the solar ray, the lecturer dwelt on its property of producing chemical change. This change was exhibited in preparations of silver, and in the coloring matter of leaves and then the molecular disturbance produced on metals under the influence of the spectral rays was described. : Having shown by means of diagrams, and experimentally with the oxy-hydrogen light, that the chemical power was least at that part of the prism where the luminosity was greatest, and that, generally, the one influence increased as the other diminished, Mr. Hunt inferred that, to obtain perspicuity in scientific language, it would be advisable to distinguish, by some specific appellation, a quality of the solar rays, so clearly different from that of producing light or heat. The term, actinism had been suggested to express this property, and, as it involves no hypothesis, it was considered provisionally useful. Examples were then adduced to show that the luminous rays acted as antagonist forces to the actinic rays, and that the chemical change produced by heat, was of a totally different character from that caused by actinism-a force which, though acting in every part of the spectrum, was most powerful beyond the limits of the influence of light and heat. Numerous examples were then adduced to show that chemical change, so far from being confined to a few so-called photographic agents, was produced on an immense variety of compound and simple bodies. In addition to the salts of silver, gold, and iron, specimens of pictures produced by the sunshine on the salts of nickel, cobalt, tin, mercury, bismuth and copper were shown, together with evidences of molecular change on plates of polished copper and tin, wood, stone, and glass. The results of these experiments being 1. That every substance in nature exposed to solar light undergoes a change. 2. That all substances have the property of restoring themselves to their original condition when this influence of solar light is removed. Therefore, the hours of darkness become not less important to the inorganic than they are to the organic creation. Among other remarkable phenomena, demonstrative of the mutually antagonistic tendencies of the actinic and luminous spectrum in producing chemical decomposition, Mr. Hunt particularly instanced the feeble chemical power of the sun's rays in those parts of the world where their luminous and calorific power is greatest, as in South America, Egypt, &c.,-the change in simple and compound solutions produced by exposure to sunshine, the development of dormant images caused by the solar ray, their obliteration, and subsequent restoration. In conclusion, Mr. Hunt avowed his conviction that philosophers were progressively attaining the knowledge of a power in nature superior to the so-called Imponderable Agents to which the great phenomena of the universe have hitherto been mainly referred, and which, in all probability, are but manifestations of this unknown power modified by agencies, which themselves must be the subject of future research. MDLLE. COTTIN, THE ELECTRIC GIRL. THE following extraordinary relation has lately attracted the notice of the savans of France, we give the statement as we find it, reserving our judgment on the subject for a future opportunity. At the sitting of the French Academy of Sciences, February 16th, it was stated that a physician of the little town of La Perrière, in Normandy, had just arrived at Paris with a young girl, who is said to present extraordinary electro-magnetic phenomena. Malle. Cottin, such is her name, makes all bodies that approach her, and with which she is put into communication, by means of a conductor, or by the mere end of one of her garments, experience a movement of repulsion that displaces, and sometimes even violently subverts them. At the same time, she herself experiences an instantaneous and irresistable attraction towards the objects that fly from her. M. Arago has witnessed several of these phenomena, and has reported them to the Academy, which has appointed a committee to investigate them. It was on the 15th of January last, at eight in the evening, that this singular electric faculty first exhibited itself. Mdlle. Cottin was busy weaving silk gloves; at a moment when she touched with her left hand a part of the frame she was working before, the piece was carried away and thrown upwards. At the same time she involuntarily rose from her chair, and it was thrown far away from her. Every time she attempted to sit down, the same repulsion took place. If she touched any article of furniture it was immediately upset. Some days after, as she was taking up a large basket of beans, the basket rapidly receded from her, and the beans were scattered all over the room. These strange phenomena greatly astonished the girl's friends. The parish priest was consulted, and he considered Mdlle. Cottin was possessed of a devil; but all the reverend gentleman's efforts to cast him out proving fruitless, a physician was sent for, who pronounced the phenomena of an electric nature, and made some experiments, which have just been repeated at Paris before several scientific persons. It is the left side of the body that seems chiefly to acquire this attractive, but, more frequently, repulsive property. ment several persons have, on touching her, felt a real electric commotion. Throughout the paroxysm, the left side of her body is warmer than the right; it is the seat of shocks, extraordinary motion, and of a sort of trembling which seems to communicate to the hand that touches it. Malle. Cottin, moreover, presents to the action of a magnet peculiar sensitiveness; when she puts her finger near the north pole, she experiences a violent shock, whilst the south pole produces no effect; so that if the person who makes the experiment happen to change the poles, without her being aware of it, she always points them out by the difference in the sensation she experiences. It would appear that no doubt can be entertained as to the phenomena observed in the young girl. We have admitted, says the editor of a Paris journal, with the physician who examined her, that these phenomena have an electric origin. Electricity alone can, indeed, produce such action; and it enacts a real part in the vital movements. In certain cases this natural electricity has increased unto being rendered perceptible with physical instruments, and even emitting sparks. In short, electric discharges are normally observed in certain animals, such as the torpedo, gymnote, &c. Some experiments would confirm this opinion. Thus, it has been several times observed that the objects touched by the girl or by her garments seemed to cling to her or them, and follow them for a moment before they were repelled. The phenomena of repulsion take place only when her feet touch the ground; they are no longer observed when she places her feet on the bars of her chair, on a floor rubbed with wax, on a piece of gummed taffety, on a plate of glass, in short, whenever she is isolated from the ground-the common reservoir of electricity. A sheet of paper, a pen, or any other light body, being placed on a table, if Mdlle. Cottin advances her left hand towards it, will, long before she has touched it, be carried afar off, as if by a gust of wind. The table itself is thrown down, the moment it is touched by the girl, or even by a thread held by her; Mdlle. Cottin also experiences a strong commotion, that draws her towards the table. But it is in the lower part of her body that this strange force of repulsion seems to concentrate itself. Thus, as was observed on the first day, when she sits down, the seat is driven from her, with such force that another person sitting on the chair is carried away with it. On one occasion, a trunk, on which three men sat, was shaken and moved in the same way. Another day, when the chair was held by two very strong men, it broke in their hands. If these phenomena continued without intervals it would be a torture to the girl. They are observed with more or less force, from time to time in the day; but their greatest intensity is in the evening, between seven The committee appointed by the academy, and nine. Mdlle. Cottin is then obliged consists of M M. Arago, Becquerel, Babinet, to stand, and she is in great agitation. Rayer, and Pariset. They will, no doubt, exShe cannot touch any thing without break-amine with due interest the curious fact, reing or throwing it down. specting which we have just given all the information we have been able to gather. All persons engaged in studying natural phenomena, All the articles of furniture that she merely grazed are displaced, and overturned. At that mo M. Arago wished to know whether the needle of a compass would deviate on the approach of the girl. No deviation took place, but perhaps the phenomena did not exist at the moment in their utmost intensity. Mdlle. Cottin is fourteen years old. Her intelligence is ordinary, and her general health good enough; yet the extraordinary movements and paroxysms observed every evening have some resemblance to what is observed in certain nervous diseases. impatiently await the result of the investigation. It is not, as we have already said, that any doubt seems to exist as to the reality of the phenomena, but it is important to ascertain in what way the supposed electric emanation of Mdlle. Cottin will act on electrometers and other instruments. IMPROPER USE OF GUANO. PROGRESS OF PHYSIOLOGY IN AMONG the notices in the Gazette Médicale, ON A NEW AND EXTRAORDINARY Ar the sitting of the Academy of Sciences Ar the great Jesuit convent La Merced, at St. Diego, Upper California, the Jesuits have known the use of guano as a manure ever since the beginning of the last century. M. La Talle, lately sent there as an inquirer by the Colonial-office, had opportunities of speaking with the Superior on the subject. He relates that after the use of guano for several years (four or five), the soil naturally fertile and very like that of the best cultivated parts of Norfolk, becomes rapidly exhausted, and unable to yield even a meagre crop; so that, while under the influence of guano, the crop was no less than 120 bushels of Indian corn per acre (considerably more than double the crop yielded by prime land in Louisiana and the Arkansas), yet after a short period of such exhausting treatment, the nutritious properties of the earth became worn out, and the soil literally (and without any figure of speech) barren. In California, the proprie-enabled to study all the mechanism of that tors are possessed of so extensive a territory, that the loss of the land is to them a matter of little moment. Besides this, they have a well-arranged system of irrigation, by means of which they convey water over the land which has ceased to be fertile, and a cooling deposit from the flood takes place; so that, although the soil is far from recovering its original value, yet after a rest of two or three years, and this treatment, it forms available pasture land. It should be further explained that the Jesuits, who wish to surround their dwellings with pleasing verdure, never use guano in the neighbourhood of their residences. M. La Talle thinks that the lesson to be gained from these facts is-not the entire abandonment of guano, but the sparing use of it, and its application chiefly to those soils which, in the language of our farmers, are called "cold clays," and seem peculiarly in need of such a powerful stimulant; but he recommends its use in conjunction with liquid manure, and thinks it ought always to be sparingly applied. Knowing from practical experience the extent to which this manure is coming into vogue, and that some farmers are thoughtlessly applying it to land of every description and in large quantities, hoping for an early and large return, I have thought it my duty not to conceal these facts from the public. important organ as if it were placed before him under a glass. The author even asserts that he has ascertained the existence of tubercles in the lungs of a consumptive patient, and gives a drawing of them as they appeared. On rubbing the skin with a little olive oil, the transparency was augmented, and he was enabled to follow the process of digestion (!) TO CORRESPONDENTS. "W.E."(Welshpool).-The last volume of The Chemist (1845), can be had at our office, or by order of any bookseller. It has never been out of print. The first vol. may be had, we believe, of Mr. Hastings, Carey-street, the former publisher. An original paper, entitled "A New Test for Manganium," by Mr. Reuben Phillips was received too late for insertion in the present number, but shall appear in our next. "DUBLIN" shall receive an answer to his question in our next number. NOTICE.-All Communications and Books for Review must be addressed "To the Publisher of THE CHEMIST, 310, Strand, London." Communications must be prepaid, and sent before the 15th of each month; Books for Review before the 10th. THE CHEMIST. I. CHEMISTRY. AN ATTEMPT TO REFUTE THE REASONING OF LIEBIG IN FAVOR OF THE SALT RADICAL THEORY.* BY ROBERT HARE, M.D. (To the Editor of Silliman's Journal.) GENTLEMEN - My attention was lately drawn to two lectures delivered about eighteen months ago, by Liebig, in support | of the salt radical theory. You are well acquainted with the efforts made by me to refute that hypothesis, in an essay published under your auspices, in a letter to the editor of Silliman's Journal. Your opinions, as well as those of several of the more distinguished of our American chemists whom I have consulted, have been emphatically expressed in favor of the validity of my reasoning. Nevertheless, from the lectures above-mentioned, and from a text-book lately published by Gregory, the successor of Hope, it appears that, by these eminent professors, innovations are to be supported which have, on this side the water, been deemed indefensible. Under these circumstances, I again raise my voice against this new doctrine, hoping that although an ocean rolls between those who may be led astray and the writer of this letter, his warning may be neither unheard nor unheeded. 2. Pursuant to the new doctrine, every oxacid is to be considered as a hydruret of a compound radical, as those heretofore called hydracids are hydrurets of simple radicals, so that both of these classes are to bear the name of hydracids. 3. Agreeably to the nomenclature proposed by Daniell, the hydrated sulphuric, nitric, and phosphoric acids consist of hydrogen, in union severally with oxysulphion, oxynitrion, and oxyphosphion: their formulæ being, respectively, SO H, NO H, PO6 H 4. According to a definition given by Liebig, at the close of his second lecture, "acids are compounds of hydrogen, with * American Journal of Science, &c. N.S., VOL. IV.-No. XL., April, 1846. simple or compound radicals, in which the hydrogen may be replaced by its equivalent amount of metal." 5. Inferring that in those oxacids which unite with water as a base, the oxygen of the water goes to form a compound radical the constitution of these acids is considered as quite analogous to that of the compounds formed with hydrogen by halogen bodies,* whether simple, like chlorine, bromine, iodine, and fluorine; or compound, like cyanogen. Hence the term hydracid, heretofore confined to the haloïd compounds of hydrogen, and those formed by this element with sulphur and selenium, is to be extended to all the hydrated oxacids. Moreover, respecting oxacids which are incapable of uniting with water as a base, the distinguished lecturer holds the following langauge :-"I maintain that they are not acids. Do you find any of the characteristic properties of the hydrogen acids, in chromic acid, boracic acid, silicic acid, titanic acid, antimonic acid, or in their combinations with metallic oxides ?" 6. The lecturer also uses the following language :-" The compound which we denominate hydrated sulphuric acid, pos * Chlorine, bromine, iodine, fluorine, and cyanogen, are by Berzelius distinguished by the generic name halogen, from Greek words which convey the idea of salt, and to produce. Common salt, from which the notion of salt first orginated, being a binary compound of chlorine and sodium, all other binary compounds of chlorine, or of any of its congeners which belong to his halogen class, are called salts, and the compounds of these double salts, although there are no bodies in nature more dissimilar in their properties than some of those thus constituted; as for instance the gaseous compounds formed with hydrogen, the volatile liquid, and fuming chlorides of tin and arsenic, the butyraceous chlorides of zinc, bismuth, and antimony, and such inert chlorides or fluorides as horn silver, horn lead, and fluor spar. T distinctive of these diluted acids, can be imagined? The evolution of hydrogen by reaction with metals, cannot avail, unless water, equally capable of that reaction, be made an hydracid, and oxygen consequently transferred to the halogen class. But if this transfer be made, the salts, heretofore con sesses properties analogous to hydrochloric acid." And again: "There is no proof that our common sulphuric acid contains water; but we can prove that its chemical character, analogous to that of hydrochloric acid, depends, as in that acid, on the presence of hydrogen. We can prove that this hydrogen can be replaced by its equiva-sidered as simple amphide salts, become as lent of metal." 7. This celebrated author has, in a preceding paragraph, urged "that the so-called anhydrous sulphuric acid, and phosphoric acid, do not possess any of the characteristic properties of acids; these they obtain only by their combination with water." well entitled to be deemed double haloïd salts, as any of the double chlorides. 10. Is it not evident that the whole of this salt radical doctrine, as presented by Liebig, is founded on an unnatural and arbitrary peculiarity, attached to oxygen on one side, and to hydrogen on the other, by which each of these elements is treated as a body sui generis? Upon what rational ground is oxygen separated from the other electro-negative elements forming the amphigen and halogen bodies of Berzelius ? 11. If chlorine be a simple radical, wherefore is not oxygen a simple radical? But if oxygen be a simple radical, agreeably to Liebig's definition above quoted, (3) water,' the oxide of hydrogen, is as much entitled to be considered as an hydracid, as muriatic acid (the chloride of hydrogen). The oxide, no less than the chloride, consists of a 8. As the characteristic properties of "the hydrogen, acids" are not only in the instances here cited, but in others, repeatedly insisted on by Liebig as a corner-stone of the new system, it is unfortunate that they are nowhere described. It is to be regretted that Liebig does not specify any properties characteristic of acidity, which belong both to the hydrated oxacids and the gaseous "hydracids" (so called,) formed by the union of hydrogen with the halogen bodies of Berzelius. Neither the latter nor the former, while undiluted, are endowed with sourness, nor with the ability to redden" radical in combination with hydrogen in litmus; and were they thus endowed, it I could not be of any importance to the argument, since according to Liebig, "We have long since abandoned the position, that mere reaction with test paper should decide whether or not a body should be called an acid or not.” But if reaction with testpaper be thus set aside, the inferior test of sourness cannot but share the same fate. 9. It seems to me that there has been a lamentable deficiency of precision in Liebig's expressions respecting the resemblance between the hydrated oxacids and the haloïd* hydracids. I call upon him, or any of the advocates of the salt radical theory, to point out any peculiar attributes of acidity belonging to them in common. The whole source of this idea would seem to be a vague conception, that the vulgar attributes of acidity belonging in common to diluted sulphuric and diluted muriatic acid, are attributable to the hydrogen of the basic water in one case, and that of the hydrogen of the gaseous chloride in the other. But to lay any stress on this resemblance, is irreconcilable with the above quoted allegation of the celebrated author, that the effect upon test-paper is uo longer to be considered as an evidence of acidity. Yet besides this attribute and that of sourness, what other common properties, *A haloïd compound is one which contains a halogen body as an ingredient. which the hydrogen may be replaced by a metal." Hence, as no rational line of demarcation can be drawn about oxygen, so as to separate it from its congener chloride, it follows, either that all the compounds consisting of two chlorides, and hitherto called double chloro-salts by Berzelius, are consistently simple chloro-salts; or, that all compounds consisting of two oxides and called simple, should be considered as double oxysalts. 12. The supposed hydracids, consisting of oxacids containing only basic water, being liquid, while the hydracids proper, when equally devoid of water, are aëriform; had the comparison been made between them, neither being associated with water as a solvent, the idea of any similitude could hardly have arisen. Besides, unless so associated they are generally insusceptible of change by reaction with metals without heat, and when subjected to decomposition, there is an analogy in the result. In the case of hydracids proper, the halogen body uniting with any metal presented to it, hydrogen is evolved; but in that of the hydrated oxacids, the alleged compound radical is decomposed with an evolution of some combination of the non-metalic ingredient with oxygen. Thus instead of hydrogen, sulphuric acid yields sulphurous acid, nitric acid yields nitric oxide. It follows that the presence of basic water alone, does not fulfil the conditions of Liebig's definition, since per se the hydrogen |