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gonite; on an arenaceous iron ore; on an unknown petrification; and an analysis of a cupreous and ferrugineous petrified wood,

Mr. Vauquelir has analysed tobacco, with a view to discover the principles that characterise this plant, and have occasioned it to be selected for the purposes for which it is employed; and also to ascertain the changes occasioned by its preparation as an ar ticle of trade. He has found, that it contains animal matter of the nature of albumen, malat of lime with excess of acid, acetic acid, nitrat and muriat of potash, a red matter, the nature of which is unknown, muriat of ammonia, and an acrid and volatile principle, which appears to differ from all others known in the vegetable kingdom This principle, which imparts to tobacco its well known qualities, may be extracted from the plant by distillation, and employed separately. In prepared tobacco were found, besides the above, carbonat of ammonia and muriat of lime.

As Mr. V. imagined, that the juice of belladonna, from its having similar effects on the animal economy, contained the acrid principle he had discovered in tobacco, he analysed it; but he found only animal matter, salts with base of potash, and a bitter substance, to which the deadlynight-shade owes its narcotic proper


Mr. Chevreul has made very extensive experiments on vegetable matters. The object of some of these was the bitter principle produced by the action of nitric acid, on ́organized substances, containing, nitrogen, and which had already occupied the attention of Hausmans, Welther, Proust, Fourcroy, and Vauquelin. Mr. C. thinks, that this bitter matter is a compound of nitric acid and an sily or resinous vegetable sub stance. The detonating property

of this substance, he ascribes to the decomposition of nitric acid, and the formation of ammoniacal gas, prussic acid, oily hydrogen gas, &c.; which agrees in part with the observations of Fourcroy and Vauquelin. With this bitter matter are produced a resinous substance, and a volatile acid, on which Mr. C. has made many experiments, and which he considers as differing from the bitter matter only by a small portion of nitric acid.

Another paper, by the same gentleman, is on the substances formed by the action of the nitric acid on carbonaceous or resinous substances, and which have the property of precipitating gelatin. Mr. C. thinks, that the discoverer of these substances, Mr. Hatchett, is mistaken in considering them as one, and the same with tannin. He conceives, on the contrary, that they differ not only from tannin, but from each other, according to the kind of acid, the quantity that enters into their composition, and the substance from which they are prepared.

Mr. C. has likewise examined the different compounds formed by the action of sulphuric acid on camphor.

Not a year has passed of late without some successful application of chemistry to the arts, so as to afford fresh proofs of the advantages that our manufactures may derive from the sciences. Thus Mr. Chaptal has given us some interesting observations on the distillation of spirits. One of the most important distilleries in the South of France is in fact a Woulfe's apparatus on a large scale.

The same chemist has analysed seven specimens of colours found at Pompeii. Three of these are earths naturally coloured, one greenish, one yellow, and the third a brown red. The fourth is a very light and very white pumice-stone. The fifth, which is of a fine rose-colour, has all the

characters of a lake, and has co siderable resemblance to the madder lake, which he has described in his treatise on dyeing cotton. The other two were blues, one pale, but the other deep and rich. They were both produced by a combination of oxide of copper, with lime and alumin, resulting from a commencement of vitrification. As this blue is much superior to verditer, and might be fabricated at a much less expense than

ultramarine, or the blue from cobalt, it would be of great advantage to discover the processes employed by the ancients for producing it.

Mr. Sage has been endeavouring to ascertain the processes best adapted to the extraction of quick-lime, for btaining solid mortars; the nature of different kinds of stucco; the means of giving the polish of marble to artificial stones; and a process for making soap of white wax.


Observations upon Luminous Animals.

By J. Macartney, esq. THE property which certain a

nimals possess of emitting light is so curious and interesting that it has attracted the attention of naturalists in all ages. It was particularly noticed by Aristotle and Pliny amongst the ancients; and the publications of the different learned societies in Europe contain numerous memoirs upon the subject. Notwithstand ing the degree of regard bestowed upon the history of luminous animals, it is still very imperfect; the power of producing light appears to have been attributed to the several creatures which do not possess it; some species which enjoy it in an eminent degree have been imperfeetly described or entirely unobserved; the organs which afford the light in certain animals have not been examined by dissection; and, lastly, the explanations that have been given of the phenomena of animal light are unsatisfactory, and in some instances palpably erroneous.

As this subject forms an interesting part of the history of organized beings, I had for some years availed myself of such opportunities as

occurred for its investigation. Hav ing communicated the result of some of my researches to the Right Hon. Sir Joseph Canks, he immediately offered me his assistance with that liberality which so eminently distinguishes him as a real lover of sci ence. I am indebted to him for an inspection of the valuable journal he kept during his voyage with Captain Cook; for permission to copy the original drawings in his possession of those luminous animals dis covered in both the voyages of Cook; and for some notes upon the Juminous appearance of the sea, that were presented to him by Captain Horsburg, whose accuracy of obser vation is already known to this learned society.

In the following paper I shall fire examine the grounds on which the property of shewing light has been ascribed to certain animals that either do not possess it, or in which its existence is questionable. Ishafl next give an account of some luminous species, of which some have been inaccurately described, and o thers quite unknown. I shall endeavour to explain, from my own observations, and the information

communicated to me by others, many of the circumstances attending the luminous appearance of the sea. I shall then describe the organs employed for the production of light in certain species; and, lastly, I shall review the opinions which have been entertained respecting the nature and origin of animal light, and relate the experiments I have made for the purpose of elucidating this part of the subject.

The property of emitting light has been reported to belong to several fishes, more particularly the mackafel, the moon-fish, (tetraodon nola) the dorado, mullet, sprat, &c.

Mr. Bajon observed, during the migration of the dorados, &c. that their bodies was covered with luminous points. These however proved, upon examination, to be mere spherical particles that adhered to the surface of these fishes; and, he adds, appeared to be precisely the same sort of points that illuminated the whole of the sea at the time. They were therefore, in all probability, the minute kind of medusa which I shall have occasion to describe hereafter.

Godeheu de Riville states, in a paper sent to the academy of sciences at Paris, that on opening the scomber pelamis while alive, he found in different parts of its body and oil which gave out much light: but it should be observed, that Riville had a particular theory to support, for which this fact was very convenient, and that other parts of his memoir bear marks of inaccuracy. It may be added, that if the oil of fishes were usually luminous, which Riville supposed, it would be almost universally known, instead of resting on a solitary observation.

As far as I am able to determine from what I have seen, the faculty of exhibiting light during life does not belong to the class of fishes. It ap


pears probable, that some fishes may have acquired the character of being luminous from evolving light soon after death.

Some species of lepas, murex, and chama, and some star fish, have been said to possess the power of shining; and the assertion has been repeated by one writer after another, but without quoting any authority.

Brugueire upon one occasion saw, as he supposed, common earth-worms in a luminous state; all the hedg

were filled with them; he remarked that the light resided prina cipally in the posterior part of the body*

Flaugergues pretended to have seen earth-worms luminous in three instances; it was at each time in October; the body shone at every part, but most brilliantly at the genital organst.

Notwithstanding this concurrence of testimony, it is next to impossible that animals so frequently before our eyes as the common earth-worm should be endowed with so remarkable a property without every person having observed it. If they only enjoyed it during the season for copulation, still it could not have escaped notice, as these creatures are usually found joined together in the most frequented paths, and in garden-walks.

In different Systems of Natural History the property of shining is attributed to the cancer pulex. The authorities for this opinion are Hablitzl, and Thules and Bernard. The former observed, upon one occasion, a cable that was drawn up from the sea exhibit light, which upon closer inspection was perceived to be covered by these insects. Thules and Bernard reported that they met with

* Journal d'Histoire Naturelle, tome II. ↑ Journal de Physique, tome XVI. Hablitzl ap. Pall. ñ. Nord. Beytr. 4, p.



a number of this species of cancer on the borders of a river entirely luminous t. I am nevertheless disposed to question the luminous property of the cancer pulex, I have often had the animal in my possession, and never perceived it emit any light.

The account by given Linneus of the scolopendra phosphorea is so improbable and inconsistent that one might be led to doubt this insect's existence, particularly as it does not appear to have been ever seen, except by Eke. berg, the Captain of an East Indiaman, from whom Linneus learnt its history.

I now proceed to the description of those luminous animals that have been discovered by the Right Honour able Sir Joseph Banks, Captain Horsburg, and myself.

On the passage from Madeira to Rio de Janeiro, the sea was observed by Sir Joseph Pauks to be unusually luminous, flashing in many parts like lightning. He directed some of the water to be hauled up, in which he discovered two kinds of animals that occasioned the phanomenon the one, a crustaceous insect, which he called the cancer fulgens; the other, a large species of medusa, to which he gave the name of pellucens.

The cancer fulgens bears some resemblance to the common shrimp; it is however considerably less; the legs are furnished with numerous sete. The light of this animal, which is very brilliant, appears to issue from every part of the body.

The medusa pellucens measures about six inches across the crown or umbella; this part is marked by a number of opake lines, that pass off from the center to the circumference.

Journal de Physique, tome XVI. + Hablitzl ap. Pall. n. Nord. Beytr. 4, p.


Journal de Physique, tome XXVIII.

The edge of the umbella is divided into lobules, which succeed each other, one large and two small ones alternately. From within the mar gin of the umbella there are suspended a number of long cord-shap ed tentacula. The central part of the animal is opake, and furnished with four thick irregularly-shaped processes, which hang down in the midst of the tentacula.

This zoophyte is the most splendid of the luminous inhabitants of the ocean. The flashes of light e mitted during its contractions are so vivid as to effect the sight of the spectator.

In the notes communicated to Sir Joseph Banks by Captain Horsburg he remarks that the luminous state of the sea between the Tropics is generally accompanied with the appearance of a great number of marme animals of various kinds upon the surface of the water; to many of which he does not, however, attribute the property of shining. At other times, when the water which gave out light was examined it appeared only to contain small par ticles of a dusky straw colour, which dissolved with the slightest touch of the finger. He likewise observes that in Bombay, during the hot weather of May and June, he has frequently seen the edges of the sea much illuminated by minute sparkling points.

At sun-rise on April 12, 1798, in the Arabian sea, he perceived several luminous spots in the water, which conceiving to be animals, he went in the boat and caught one. It proved to be an insect somewhat resembling in appearance the woodlouse, and was about one third of an inch in length. When viewed with the microscope it seemed to be formed by sections of a thin crustaceous substance. During the time that any fluid remained in the api

mal it shone brilliantly, like the fire-fly.

In the month of June in the same year he picked up another luminous insect on a sandy beach, which was also covered with a thin shell, but it was a different shape, and a larger size than the animal taken in the Arabian sea.

By comparing the above descrip. tion with an elegant pen and ink drawing which was made by Captain Horsburg, and accompanied his paper, I have no doubt that both these insects were monoculi; the first evidently belongs to the genus limulus of Muller; I shall therefore beg leave to distinguish it by the name of limulus noctilucus,

My pursuits and the state of my health having frequently led me to the coast, I have had many opportunities of making observations upon the animals which illuminate our own seas. Of these I have discovered three species: one of which is a berve not hitherto described by authors; another agrees so nearly with the medusa hemispherica that 1 conceive it to be the same, or at least a variety of that species; the third is a minute species of medusa, which I believe to be the luminous animal so frequently seen by navigators, although it has never been distinctly examined or described.

I first met with these animals in the mouth of October 1804, at Herne Bay, a small watering place upon the northern coast of Kent. Having observed the sea to be extremely luminous for several nights, I had a considerable quantity of the water taken up. When perfectly at rest, no Tight was emitted; but on the slightest agitation of the vessel in which the water was contained, a brilliant scintillation was perceived, particularly towards the surface; and when the vessel was suddenly struck, a flash of light issued from the top of

the water, in consequence of so many points shining at the same moment. When any of these sparkling points were removed from the water, they no longer yielded any light. They were so transparent that in the air they appeared like globules of water. They were more minute than the head of the smallest pin. Upon the slight est touch they broke and vanished from the sight. Having strained a quantity of the luminous water, a great number of these transparent corpuscles were obtained upon the cloth, and the water which had been strained did not afterwards exhibit the least light. I then put some sea-water that had been rendered particularly clear, by repeated filtrations, into a large glass, and having floated in it a fine cloth, on which I had previously collected a number of luminous points, several of them were liberated, and became distinctly visible in their natural element, by placing the glass before a piece of dark coloured paper. They were observed to have a tendency to come to the surface of the water; and after the glass was set by for fome time, they were found congregated together, and when thus collected in a body they had a dusky straw colour, although individually they were so transparent as to be perfectly invisible, except under particular circumstances. Their substance was indeed so extremely tender and delicate, that they did not become opaque in distilled vinegar or alcohol until immersed in these liquors for a considerable time.

On examining these minute globules with the microscope, I found that they were not quite perfect spheres, but had an irregular depression on one side, which was formed of an opaque substance, that projected a little way inwards, producing such an appearance as would arise from tying the neck of a round

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