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all bodies radiate heat in the same way as luminous bodies radiate light; that the radiation between contiguous bodies isreciprocal, and that when there is no other body contiguous to the radia

pursuit of my own trains of thought; in proof of which, I may perhaps be allowed to say, that in the fourteen years following this illness, I made more literary efforts than I had done during the whole preceding period of my life. Dreading, how-ting one, the latter cools very rapidly. ever, another attack of apoplexy, or one of palsy, warnings of which I had almost daily since that time received, I determined to live most abstemiously, and in consequence, took not more food when I was at home (I dined there about four or five times a week) than was sufficient for a child of seven years old, and that consisting of vegetable matter. p. xxxiii.

He never had another fit of apoplexy, but his health was much weakened, and it was, as we have already remarked, an instance of great perseverance, and of an ardent philosophical mind, that he carried on his experiments on Dew in the state in which he was.

"I was at last (he says) obliged to desíst. I became breathless on slight motion;

and was frequently attacked with palpitation of my heart. My friend Dr Lister became alarmed at my situation, and strongly urged my remaining quiet, as he thought it impossible I should survive more than a few months. Upon receiving this opinion, I set about immediately composing my Essay on Dew, as my papers containing the facts on which my theory was founded, would, after my death, be altogether unintelligible to any person who should look into them. I laboured in consequence for several months with the greatest eagerness and assiduity, fancying that every page I wrote was something gained from oblivion." p. xxxvi.

This essay, composed under all these disadvantages, is quite a model of philosophical induction, and we could not, we think, in the whole range of our modern literature, select any small work more characteristic of the Baconian philosophy, or more adapted to stimulate the exertions of a young experimentalist, or to set him a better example of accurate and minute investigation. To the work itself, and to Professor Leslie's article Dew in the New Supplement to the Encyclopædia Britannica, we refer for more ample details than we can give here, and shall content ourselves with an account of one or two of his simple and beautiful experiments on a phenomenon of daily occurrence, yet formerly so little understood. The whole, indeed, form a very striking illustration of the doctrine of heat, as elucidated by Prevost and Leslie, namely, that

On this principle, which is now rather more than a theory, Dr Wells explained the fact which was observed more than two thousand years ago by Aristotle, that no dew falls on a cloudy night, and the clearer the sky, the more copious the dew. To use the words of Prevost, "Ainsi la chaleur rayonnante de la terre traverse avec facilité l'atmosphère pure, mais elle ci font donc pour la terre une espèce est interceptée par les nuages. Ceux

de vêtement. Ils empèchent l'écoulement de sa chaleur rayonnante; et en la recevant vers leur partie inférieure, ils s'échauffent de ce côté-la, comme un habit s'échanffe du côté du corps et par conséquent ils renvoient à la terre un peu plus de chaleur rayonnante que ne peut faire l'air transparent." (Recherches sur la Chaleur.)

Dr Wells thus proves the correctness of the explanation by a very simple experiment.

"I placed, on several clear and still nights, 10 grains of wool upon the middle of a painted board 4 feet long, 2 feet wide, and 1 inch thick, elevated 4 feet above the grass plat, by means of 4 slender wooden props of equal height, and, at the same time, attached, loosely, 10 grains of wool to the middle of its under side. The two parcels were consequently only an inch asunder, and were equally exposed to the action of the air. Upon one night, however, I found that the upper parcel had gained 14 grains in weight, but the lower only 4. On a second night, the quantities of moisture, acquired by like parcels of wool, in the same situations as in the first experiment, were 19 and 6 grains; on a third, 11 and 2; on a fourth, 20 and 4; the smaller quantity being always that which was gained by the wool attached to the lower side of the board." p. 138. It follows from this, which was found to occur invariably in the same circumstances, that "whatever diminishes the view of the sky, as seen from the exposed body, occasions the quantity of dew which is formed upon it to be less than would have occurred, if the exposure to the sky had been complete." He observed, that on a cloudy night, a piece of glass, laid over an earthen pan containing water, and placed upon the ground, to be

wet on its lower side, while the upper was dry; the glass being, in this situation, sufficiently cold to condense the vapour of water heated by the earth, but not enough so to condense the watery vapour of the atmosphere. But we will not deprive our philosophical readers of a great feast by giving them any more broken morsels. We are sure that no one fond of such inquiries will begin the Essay on Dew, without going on delighted

to the end.

We shall now give a short account of Dr Wells's equally beautiful experiments on Single and Double Vision-a subject which has long been a stumbling-block to philosophers. He controverts the opinion first broached by Aguilonius, and adopted by Dechales, Porterfield, Dr Smith of Cambridge, and Dr Reid of Glasgow, that an object is seen single by both eyes, because it is seen by each of them in the same external place, in consequence of an original law of perception: And if we may venture an opinion on a subject so abstruse, we think he has succeeded in making good his ground. We cannot, how ever, afford room to detail his masterly arguments, which are equally interesting to the metaphysician and the natural philosopher. The experiments are so simple, that most of them may be easily repeated without much apparatus. For example,

"Take three strings of different colours, as red, yellow, and green, and fasten, by means of a pin, one end of each to the same point of a table. Place now their loose ends in such a manner, that when you look at the pin with both eyes, the visual base being parallel to the edge of the table, the red string may lie in the axis of the right eye, the green in that of the left, and the yellow in the common axis. When things are thus disposed, and both eyes directed to the pin, the red and green strings, instead of appearing separate, each in one of the optic axes, and inclined to the visual base, or edge of the table, will now be seen occupying but one place, either together or successively, and at right angles to the visual base or edge of the table; in short, exactly in the situation, which the yellow string in reality possesses; and the yellow string, instead of appearing single in the common axis, and perpendicular to the visual base, will now be seen as two, each inclined to the base; that seen by the right eye, apparently occupying the place in reality possessed by the green string, and that

seen by the left eye, the place of the red string." p. 41.

Another very elegant experiment, with strings of different colours, will be sufficient, we think, to tempt our optical readers to peruse the whole.

"When a red string was placed in the axis of the right eye, and a green one in that of the left, I said that they both apBut this is peared in the common axis. with respect to their apparent number in not the only phenomenon to be observed this experiment. For as the red string is also seen by the left eye, and the green by the right, two other strings become visible, beside that in the common axis, the apparent positions of both of which will be found to be the same with those which ought to follow, from the principles we have laid down. Should now a yellow string be placed between the two former, as in the proof of the second proposition, the space between the appearances of the its appearance to the right eye will bisect

red and green strings to that eye; and the like will be true with respect to the appearances of the three strings to the left eye." p. 44.

So that, objects situated in any line drawn through the mutual intersection of the optic axes to the visual base, do not appear to be in that line, but in another, drawn through the same intersection, to a point in the visual base distant half this base from the similar extremity of the former line towards the left, if the objects be seen by the right eye, but towards the right if seen by the left eye; and this holds quite generally.

The Letter to Lord Kenyon, here for the first time published, though formerly printed for private distribution, is upon a local subject-the terms of admission into the Faculty of Physicians in London, and might be supposed, on that account, to have no general interest. But we have read it with much pleasure, and we think that it must be interesting to all bodies of literary men, particularly those of the medical profession, as it contains many minute details concerning the state of medical practice in London. Our author has also, in this letter, made many sensible observations on the laws and politics of Britain, which show that his knowledge was by no means confined to his own profession.

With all the merits of these productions, however, we are not sure

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that this book is likely to be popular,
except among men of science, be-
cause experiments and sound philoso-
phy, although very engagingly brought
forward in it, take up pages which
lighter readers would have liked better
if they had contained more wonders of
the species, which we shall now briefly
lay before them, as a finale to our very
meagre abstract of its contents.

Account of a Female of the White
Race of Mankind, part of whose
Skin resembles that of a Negro.

Hannah West, now (1814) in the
twenty-third year of her age, was born
of English parents in a village in Sus-
sex, about three miles distant from
the sea.
Her parents had nothing
peculiar. Her mother is still alive,
and has black hair, hazel eyes, and a
fair skin without any mark. Han-
nah was her only child by her first
husband; but her mother has had
eleven children by a second marriage,
all without any blackness of the skin.
The young woman is rather above
the middle size, of full habit, and has
always enjoyed good health. Her
hair is light brown and very soft, her
eyes faint blue, her nose prominent
and a little aquiline, her lips thin,
the skin of her face, neck, and right
hand, very fair. In every respect, in-
deed, she is very unlike a negro; it is,
consequently, very singular that the
whole of her left shoulder, arm, fore-
arm, and hand, should be of the ge-
nuine negro colour, except a small
stripe of white skin about two inches
broad, which commences a little be-
low the elbow, and runs up to the
arm-pit, joining the white skin of the
trunk of the body. Dr Wells adds a
great many other circumstances re-
specting this singular female, and
gives, in his philosophizing manner,
several ingenious reasonings concern-
ing the difference in colour among the
human species, to which, as we can-
not spare room for detailing them, we
refer those who are curious about
- such speculations.

R.

THOUGHTS ON TASTE. * INSTEAD of making a disposition to find fault a proof of taste, I would

This Essay is a conclusion of some thoughts on the same subject, in our Number for October 1818.

reverse the rule, and estimate every one's pretensions to taste by the degree of their sensibility to the highest and most various excellence. An indifference to less degrees of excellence is only excusable, as it arises from a knowledge and admiration of higher ones; and a readiness in the detection of faults should pass for refinement only as it is owing to a quick In a word, true taste consists in symsense and impatient love of beauties. pathy, not in antipathy; and the reaccounted a virtue when it implies a jection of what is bad is only to be preference of and attachment to what is better.

There is a certain point, which may be considered as the highest point of perfection at which the human faculties can arrive in the conception and execution of certain things: to be able to reach this point in reality is the greatest proof of genius and power; and I imagine that the greatest proof of taste is given in being able to appreciate it when done. For instance, I have heard (and I can believe) that Madame Catalani's manner of singing "Hope told a flattering tale," was the perfection of singing; and I cannot conceive that it would have been the perfection of taste to have thought nothing at all of it. There was, I understand, a sort of fluttering of the voice and a breathless palpitation of the heart, (like the ruffling of the feathers of the robin-redbreast,) which completely gave back all the uneasy and thrilling voluptuousness of the sentiment; and I contend that the person on whom not a particle of this expression was lost, (or would have been lost, if it had even been finer,) into whom the tones of sweetness or tenderness sink deeper and deeper as they approach the farthest verge of ecstacy or agony, he who has an ear attuned to the trembling harmony, and a heart

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point, is the best judge of music,pierceable" by pleasure's finest not he who remains insensible to the matter himself, or, if you point it out to him, asks, "What of it?" I fancied that I had a triumph some time ago over a critic and connoisseur in music, who thought little of the minuet in Don Giovanni; but the same person redeemed his pretensions to musical taste in my opinion by saying of some passage in Mozart, “This

is a soliloquy equal to any in Hamlet!" In hearing the accompaniment in the Messiah of angels' voices to the shepherds keeping watch at night, who has the most taste and delicacy, he who listens in silent rapture to the silver sounds, as they rise in sweetness and soften into distance, drawing the soul from earth to heaven, and making it partaker of the music of the spheres, or he who remains deaf to the summons, and remarks that it is an allegorical conceit?Which would Handel have been most pleased with, the man who was seen standing at the performance of the Coronation anthem in Westminster Abbey, with his face bathed in tears, and mingling "the drops which sacred joy had engendered" with that ocean of circling sound, or with him who sat with frigid, critical aspect, his heart untouched and his looks unaltered as the marble statue on the wall? *-Again, if any one, in looking at Rembrandt's picture of Jacob's Dream, should not be struck with the solemn awe that surrounds it, and with the dazzling flights of angels' wings like steps of golden light, emanations of flame or spirit hovering between earth and sky, and should observe very wisely that Jacob was thrown in one corner of the picture like a bundle of clothes, without power, form, or motion, and should think this a defect, I should say that such a critic might possess great knowledge of the mechanical part of painting, but not an atom of feeling or imagination. + Or who is it that, in

*It is a fashion among the scientific or pedantic part of the musical world to deery Miss Stephens's singing as feeble and insipid. This it is to take things by their contraries. Her excellence does not lie in force or contrast, but in sweetness and simplicity. To give only one instance. Any person who does not feel the beauty of her singing the lines in Artaxerxes, "What was my pride is now my shame," &c. in which the notes seem to fall from her lips like languid drops from the bending flower, and her voice flutters and dies away with the expiring conflict of passion in her bosom, may console himself with the possession of other faculties, but assuredly he has no ear for music.

There is a very striking and spirited picture of this subject by an ingenious living artist, (Mr. Alston,) in the present exhibition of the Royal Academy. The aca

looking at the productions of Raphael or Titian, is the person of true taste? He who finds what there is, or who finds what there is not in each? Not he who picks a petty vulgar quarrel with the colouring of Raphael or the drawing of Titian is the true critic and the judicious spectator, but he who broods over the expression of the one till it takes possession of his whole scul, and who dwells on the tones and hues of the other till his eye is saturated with truth and beauty, for by this means he moulds his mind to the study and reception of what is most perfect in form and colour, instead of letting it remain empty, " swept and garnished," or rather a dull blank, with " knowledge at each entrance quite shut out.' He who cavils at the want of drawing in Titian is not the most sensible to it in Raphael; instead of that, he only insists on his want of colouring. He who is offended at Raphael's hardness and monotony is not delighted with the soft, rich pencilling of Titian; he only takes care to find fault with him for wanting that which, if he possessed in the highest degree, he would not admire or understand. easy to be accounted for. First, such a critic has been told what to do, and follows his instructions. Secondly, to perceive the height of any excellence, it is necessary to have the most exquisite sense of that kind of excellence through all its gradations: to perceive the want of any excellence, it is merely necessary to have a negative or abstract notion of the thing, or perhaps only of the name. Or, in other words, any the most crude and mechanical idea of a given quality is a measure of positive deficiency, whereas none but the most refined idea of the same quality can be a standard of superlative merit. To distinguish the finest characteristics of Titian or Ra

And this is

demic skill displayed in it is admirable, and many of the forms are truly elegant and beautiful; but I may be permitted to add, that the scene (as he represents it) too much resembles the courtly designs of Vitruvius or Palladio, rather than "a temple not made with hands, eternal in the heavens;" and that the angels seem rather preparing to dance a minuet or grand bal let on the marble pavement which they tread, than descending the air in a dream of love, of hope, and gratitude.

phael, to go along with them in their imitation of Nature, is to be so far like them to be occupied only with that in which they fell short of others, instead of that in which they soared above them, shows a vulgar, narrow capacity, insensible to any thing beyond mediocrity, and an ambition still more grovelling. To be dazzled by admiration of the greatest excellence, and of the highest works of genius, is natural to the best capacities, and the best natures; envy and dulness are most apt to detect minute blemishes and unavoidable inequalities, as we see the spots in the sun by having its rays blunted by mist or smoke. It may be asked, then, whether mere extravagance and enthusiasm are proofs of taste? And I answer, no, where they are without reason and knowledge. Mere sensibility is not true taste, but sensibility to real excellence is. To admire and be wrapt up in what is trifling or absurd, is a proof of nothing but ignorance or affectation on the contrary, he who admires most what is most worthy of admiration, (let his raptures or his eagerness to express them be what they may,) shows himself neither extravagant nor" unwise." When Mr Wordsworth once said that he could read the description of Satan in Milton,

"Nor seem'd

Less than archangel ruin'd, and the excess Of glory obscur'd,”

till he felt a certain faintness come over his mind from a sense of beauty and grandeur, I saw no extravagance in this, but the utmost truth of feeling. When the same author, or his friend Mr Southey, says, that the Excursion is better worth preserving than the Paradise Lost, this appears to me, I confess, a great piece of impertinence, or an unwarrantable stretch of friendship. Nor do I think the preference given by certain celebrated reviewers, of Mr Rogers's Human Life over Mr Wordsworth's Lyrical Ballads, founded on the true principles of poetical justice; for something is, after all, better than nothing.

We have not ventured to make any change in the words of the ingenious essayist, although we are by no means ourselves of opinion either that Mr Rogers's poem on Human Life is nothing, or Mr

To hasten to a conclusion of these desultory observations. The highest taste is shown in habitual sensibility to the greatest beauties; the most general taste is shown in a perception of the greatest variety of excellence. Many people admire Milton, and as many admire Pope, while there are but few who have any relish for both. Almost all the disputes on this subject arise, not so much from false, as from confined taste. We suppose that only one thing can have merit; and that, if we allow it to any thing else, we deprive the favourite object of our critical faith of the honours due to it. We are generally right in what we approve ourselves; for liking proceeds from a certain conformity of objects to the taste; as we are generally wrong in condemning what others admire; for our dislike mostly proceeds from our want of taste for what pleases them. Our being totally senseless to what excites extreme delight in those who have as good a right to judge as we have, in all human probability implies a defect of faculty in us, rather than a limitation in the resources of nature or art. Those who are pleased with the fewest things, know the least; as those who are pleased with every thing, know nothing. Shakespeare makes Mrs Quickly say of Falstaff, by a pleasant blunder, that "Carnation was a colour he could never abide." So there

Wordsworth's Lyrical Ballads only something. We have long intended to give our readers some quotations from the first of these poets, whose late work we have unaccountably passed over; and we hope yet to do so. We owe likewise an amende honorable to Mr Wordsworth, who, by the way, has now added a Benjamin to his Bell, and we shall certainly give it These are poets him one day or other. whom it is never too late to take up, because they are among our classics, and Milton. Who told this lively writer that we speak of them as we do of Pope or

We

Mr Southey ever preferred the Excursion to the Paradise Lost? He might, perhaps, have traced, with truth, some resem blance in the genius of the two poets. wish our essayist would carry his own principles throughout, and think it a proof of taste to admire poets of his own as well as of former days, or at least let him End all dispute, and fix the year precise, When British bards begin t' immortalize!

ED.

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