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ing to black; as opaque, but reflecting light from numerous brilliant points and facets of hornblende and feldspar. Dr. Kennedy says it is composed of silica 48, alumina 16, lime 9, soda 4, oxide of iron 16, mur. acid 1, water 5.

Of this substance 31cwts. were melted in a reverberatory furnace, heated to the usual degree for puddling iron, in 4 hours; and every precaution was taken to ensure the slow cooling of the mass, by filling the furnace with fuel, and closing every aperture. At the end of a fortnight, the fuel was all consumed, and, the furnace having been taken down, the basalt was found in a solid mass, still too hot to hold, above 5 feet long, 4 feet wide, and 18 inches thick.

Upon breaking it, the following were the appearances presented : an upper stratum of vesicular stony matter, about an inch in thickness; evidently the production of the ebullition of the liquid matter, caused by the escape of its gaseous constituents from the action of the heat. Next, a layer of black glass, from two to eight inches thick, on the side of the mass that was exposed to the air from the doors of the furnace; elsewhere, immediately under the vesicular covering, the solid stone occurred, interspersed, however, here and there, with air bubbles, but otherwise very little different from the structure of the basalt before it had been submitted to the fire; possessing the same crystalline appearance, but distributed in a more regular manner, for, in most instances, the crystals and facets seemed to radiate from central spots.

As the quantity of basalt melted was greater than has ever been before experimented on, and as the slow cooling of the bulk was ensured by the gradual consumption of the supply of fuel, it was hoped that something analogous to, if not resembling, the columnar structure, might be discovered, upon breaking the mass. But although this expectation was frustrated, yet several varieties of structure were observed intermediate to the black glass and the perfect stone, which the writer considered worthy of being pointed out to the society, particularly as they differed, in some degree, from the results obtained by Mr. Gregory Watt from a similar experi

ment.

From the experiment of melting basalt, originally made by Sir James Hall, and repeated by Mr. Watt, Dr. Corrie, and Dr. Ward, it is certain that basalt melted and cooled quickly always becomes a black glass; and that its return from the vitreous to the stony state depends entirely upon the rate of its cooling. The melting point of basalt is about 38°, Wedgewood; and if it be suddenly lowered from this degree to 21° it becomes a black glass; but if gradually lowered to 28° it then begins to crystallize, and becomes stony, and this stony structure is the more perfect the longer the mass is kept at the same temperature, and the more gradually it passes through the intermediate degrees between 28 and 21. The same rule holds in an increasing as well as in a decreasing temperature: thus, the glass heated to 21°, and raised slowly to 28°, assumes the crystalline state, but not if the heat be augmented rapidly. It is remarka

ble that the crystallization takes place at a much lower temperature (21°) than that necessary to fuse the glass, which is considerably above 30°; and this is the case not only with the glass of basalt, but also in common green-bottle glass, which, when held in the fire for some time, in a heat just sufficient to soften it, loses its vitreous form, and becomes a substance of a mixed glassy and crystallized structure, known as Reaumur's Porcelain.

In the specimens of the melted mass exhibited by Dr. Ward, these changes were very distinctly traceable. The first appearance observed in the glass was that of exceedingly minute, distinct, or clustered globules, or spherules, of a grey colour, which, when examined by a lens, exhibited a radiating structure, and a radiant brilliancy, similar to that of wavellite or zeolite. As they increased in number they pressed upon each other, till they became so numerous and closely set as to resemble fish-roe; and a still greater degree of compression gave the whole mass the appearance of jasper or plum. bago, though the separate globules might still be traced in it. Such was the result where the development of the spherules was equal and synchronous; but in many parts of the glass they were observed to be distinct, and these seemed to grow, by the addition of concentric coats, to the number of three or more, like the coats of an onion, but preserving their radiated structure. In the jasperine substance, also, some spherules appeared to outstrip the rest in their growth, and to absorb them, as it were, into themselves, by shooting out their radii all round, and comprising them within the circuit of their new layers. But as the radii extended outwards, the centre became more stony and amosphous in its appearance and texture; its colour deepened, and some appearance of crystals was recognizable. The spherules, when of a certain size, but smaller in the jasperine matter than in the glass, changed, also, in the colour of their radii, which now assumed a brownish rusty tinge, somewhat resembling brown hæmatite, from their being apparently covered by a thin coating of rust, which was also observable where two or more were in contact, at the line of junction. Many of the spherules, by their mutual compression, were formed into irregular polygons; and it was from observing this structure that Mr. Gregory Watt framed his theory of the formation of basaltic columns. But at this period the stony basaltic structure is not completed, for the radii and concentric circles are still distinguishable, whereas in the columns nothing of the kind is discernable. The last change remarked was the coalescing of the polygons into one mass, leaving the only trace of their separate formations in their centres, now radiated in crystals, and no longer in lines. This last form was not attained nor believed to exist by Mr. Watt, as his experiment-being made upon a less quantity of basalt, which was cooled more rapidly than Dr. Ward's specimens-stopped short at the formation of the polygons. Dr. Ward concluded his paper with a comparison of the crystals and spherules of basalt with those observed in slags of glass, iron, and other metals; and hinted the possibility of imitating, by

slow cooling, combined with pressure, many crystalline bodies. He also suggested (from the observation of the gradual increase of magnetic power in basalt in passing from the glassy to the stony struc ture) the idea that crystallization, if not dependent upon, may be much influenced by, electricity.

CHELTENHAM

LITERARY AND PHILOSOPHICAL INSTITUTION.*

DURING the past session, Dr. Conolly has delivered two highly interesting lectures on "Physical Education." After adverting to the system adopted among the nations of old, especially the Greeks and Persians, and having given a general outline of the aim and end of physical education, Dr. Conolly considered its principles with reference to food, air, and exercise; examining and explaining the laws which should regulate each, in order to secure the bodily and mental health of the patient. He further divided his subject, with reference to age, into infancy, childhood, and adolescence, to the first of which his observations in his introductory lecture mainly applied; childhood and adolescence being reserved for the second lecture. The discussion of such subjects as diet, clothing, and cleanliness, afforded the lecturer an opportunity to reprobate many of the prevailing errors and deep-rooted prejudices which even still continue to retain their hold upon society; concerning the early training and education of infants; and to advocate sounder and more rational views in these respects; as well as to throw out many practical hints and suggestions for the moral government and regulation of the temper and disposition of children generally. In the second lecture the learned doctor confined himself to an application of the principles already laid down in reference to youth and adolescence. The evils pertaining to the present systems of physical education, particularly as regards females, were described at some length, and their injurious consequences strongly deprecated. The differences of the modes of training generally adopted in the education of boys and girls were pointed out, and their respective advantages and disadvantages commented upon, and illustrated by instances of daily occurrence. The paramount importance of a due attention to the exercise of young ladies at school was insisted upon, in language at once forcible and convincing. The eloquent lecturer then proceeded to inquire into the causes of that precocity of intellect which is so frequently observable in youth, and explained the methods which, in reference to the education of children thus distinguished, should be pursued, as also those which should be employed

* Abridged from The Looker-On.

in the opposite cases, of dullness, and a tardier intellectual development. Some very important observations on the clothing of the young of both sexes were offered; and the lecture concluded with a brief review of the principal features comprehended by the subject of physical education, as treated of upon the present occasion.

At a subsequent meeting of the members of the Institution, Mr. C. Hale delivered a lecture on the Natural History of the Salmon, which proved highly interesting, from the number of important facts and piscatorial anecdotes with which it was interspersed. Disclaiming, in his introduction, all pretensions to originality on a subject which had been already so ably treated of in many published works upon the subject, and to several of which he referred for those scientific details unnecessary in such a popular view as he then proposed bringing before the meeting, Mr. Hale took the evidence given in the Parliamentary Report upon our Salmon Fisheries as the basis of his discourse; and treated successively of the peculiar habits and instincts of this fish, the seasons of its visiting our bays and rivers, and the methods of catching pursued in different countries, many of which were highly curious. He also inquired into the causes of the superior flavour for which the salmon of certain rivers had ever been celebrated, particularly those of the Severn and the Thames; the reasons of the annually increasing scarcity of the fish, and the consequent increase of price: in short, the lecturer touched upon all those points best adapted to afford pleasing information to his audience, without dwelling too long or too minutely upon any one in particular.

Mr. Wilderspin has delivered two lectures on Infant Education : in the first he took a review of the rise and progress of the system, and discussed, with his accustomed ability and address, several of its leading principles and modes of instruction. The graver portions of the lecture were enlivened with a variety of highly interesting anecdotes, illustrative of the views propounded and explained. In the second the able and benevolent lecturer resumed the consideration of his subject, and explained the methods adopted in training the minds of his juvenile scholars to a right apprehension of the principles of virtue, and the moral obligations of society. He also further developed the working of the system in its connexion with the duties and objects of education; and concluded a most highly interesting and instructive lecture by some valuable hints to parents and instructors generally.

Considerable interest was excited by the discourse delivered by Dr. Boisragon, the president of the Institution, "On the Progress of Physical Science, with some considerations on the Doctrine of Final Causes, with the Relation of Man to the Material World." An elaborate and eloquent introduction, in which the full scope and objects of the discourse were beautifully explained, presented the learned president an opportunity of glancing at the nature of the evidence afforded by the ruins of primeval creation, in illustration of the doctrine of final causes, and of rapidly reviewing the state of physical

science in the ancient world. The laws and instincts which first impelled and directed man in his inquiries into the causes of those appearances, and the state of things observable around him, were inquired into, and the various phenomena in nature which must have first attracted his attention, and excited his curiosity to search into their hidden causes, as leading the way to correct and scientific knowledge in matters of science, were ably, though of necessity briefly, discussed. This division of the subject comprehended a review of the origin and rise of the study of natural history, the laws of motion, and the most celebrated theories of mathematical and astronomical science entertained by the ancients; from which the discourse passed on to a consideration of the progress of modern philosophy, in its principal and most important branches; the recent discoveries in respect of light and optics being selected as an illustration of the progress which physical science was now making. The structure of the world we inhabit, through all its states and changes, invited, nay, commanded, man to exercise his intellectual faculties in the discussion of subjects like the present, conducting him, as such discussions must do, to a right appreciation of the great first cause. The efforts of modern philosophers in directing attention to the doctrine of final causes, were warmly applauded, and their valuable discoveries, in physiology and geology especially, were referred to, as affording abundant evidence in proof and illustration of the value and importance of such efforts. The doctrine of final causes was further illustrated by the beautiful discoveries of Harvey on the circulation of the blood, and in botanical science by the changes which plants undergo in accommodating themselves to climates and latitudes not naturally congenial to them. The structure of the eye, in a great variety of animals, was adduced as another proof, and explained by a series of appropriate transparencies, for the loan of which the lecturer acknowledged himself indebted to Mr. Wright, whose able lectures on comparative physiology had been delivered before the society in the early part of the session. The extent and importance of modern discoveries, as conducing to the general happiness and prosperity of mankind, were brought into striking contrast with the ignorance of past ages; and the satires of Swift, and the witticisms of the wits of Queen Anne's days, afforded a legitimate opportunity for a forcible and eloquent appeal in behalf of the progress of physical science, and deprecative of those false views in philosophy which, for so long a period, had deluded men, under the sophism of "the wisdom of our ancestors." In conclusion, the learned president passed in review the principal features of the discourse-alluded to the important discoveries daily making in the application of the power of steam-in the infant science of geology, and the various physical phenomena which are developed in the different strata and their distinguishing fossil remains to astronomy, and particularly to the discovery of the double stars-and, finally, to electro-magnetism, and the splendid investigations of Dr. Faraday.

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