' mingled in the crowd of soldiers, sailors, statesmen, and divines, 'who thronged the splendid apartments of St. James's, where he was very graciously received by the king.' Whether his London friends acted wisely in introducing such a man to his majesty, not as John Dalton, the great chemist, but as Dr. Dalton, of Oxford, we shall not stop to inquire.

In 1834, Dalton attended the meeting of the British Association at Edinburgh, where every sort of kindness and new honours awaited him. The university conferred upon him the degree of LL.D., the Royal Society elected him a member, and the town council presented him with the freedom of the city.

In 1835, he was present at the Dublin meeting of the association; where all parties, from the lord-lieutenant downwards, vied with each other in extending to him the marks of their

esteem.

We have now reached the seventieth year of his laborious career, and it will not surprise the reader that the silver cord should be beginning to be loosed, the golden bowl to be broken at the fountain.

In 1837, when in his seventy-first year, he suffered from a severe attack of paralysis, which left his right side powerless, and also deprived him of speech. He experienced a second slight attack on the 21st of the same month, and for some time both his mental and bodily faculties appeared to be much affected. After an illness of some months, however, his health improved, and his mind began to evince something of its former vigour, though his articulation always remained less distinct than before. We are indebted to the Manchester Guardian for these particulars, and from the same able journal we take, with a few slight alterations, the following statements relative to the close of the career of John Dalton:-On the 17th of May, 1844, he had a third paralytic stroke, which partially deprived him of the use of his right side, and increased the indistinctness of his utterance. He recovered in some degree from this attack also, and on the 19th of July, 1844, was present at a meeting of the council of the Manchester Literary and Philosophical Society, where he received an engrossed copy in vellum of a resolution of that society, passed at its annual meeting, recording their admiration of the zeal and perseverance with which he has deduced the mean pressure and temperature of the atmosphere, and the quantity of rain for each month and for the whole year; with the prevailing direction and force of the wind at dif'ferent seasons in this neighbourhood, from a series of more than two hundred thousand observations, from the end of

the year 1793 to the beginning of 1844, being a period of half 'a century.' Dalton received the resolution sitting, and being unable to articulate a reply, handed a written one which he had prepared to his old and attached friend, Peter Clare, Esq., who read as follows:- I feel gratified by this testimony of kind regard offered to me by my old associates of the Literary and 'Philosophical Society of Manchester. At my age, and under my infirmities, I can only thank you for this manifestation of "sentiments which I heartily reciprocate.'

This was the 19th of the month; on the 27th, Dalton was no more!

On Friday, the 26th of July, he retired to his room about a quarter or twenty minutes after nine o'clock; and going to his desk, on which were usually placed the books in which he recorded his meteorological observations, he entered therein the state of the barometer, thermometer, &c. at nine o'clock; and added, in the column for remarks, the words little rain,' denoting that but little had fallen during the day. His servant observed that his hand trembled more than he had ever before seen it, and that he could scarcely hold the pen. Indeed, the book exhibits, in its tremulous characters and blotted figures, striking proofs of the rapid decay of the physical powers. But there was the same care and corrective watchfulness as ever manifested in this his last stroke of the pen; for, having written opposite a previous observation, little rain this,' he now noticed that the sentence was incomplete, and added the word' day,' which was the last word that was traced by his tremulous pen. He retired to bed about half-past nine, and spent a restless and uneasy night, but seemed, on the whole, in his usual way when his servant left his bedside at six o'clock next morning.

About half-an-hour later, bis housekeeper found him in a state of insensibility, and before medical attendance could be procured, though it was immediately sent for, he expired, passing away without a struggle or a groan, and imperceptibly, as an infant sinks into sleep.'

The news of Dalton's death, although it must have been looked for by many, was heard with sorrow throughout the whole length and breadth of the land. His townsmen, anxious to express their sense of the irreparable loss they had sustained, resolved to give him a public funeral. But this was not enough; and as an additional mark of respect, his body was laid in state' for a day in the Manchester town-hall, and visited by about forty thousand persons. The funeral itself took place on the 12th of August. A procession was formed of nearly a hundred carriages, and 6 many hundred persons on foot; the windows were lined with

'spectators, as well as the roofs of the houses; nearly all the shops ' and warehouses in the line of the procession, and many in other 'parts of the town, were closed; four hundred of the police were 'on duty, each with an emblem of mourning; and the funeral 'train was about three quarters of a mile in length.' He was buried in the cemetery at Ardwick Green. It has been felt by many that it would have been well if the lying in state' at least had been omitted. It lessens the pleasure also with which we otherwise read the accounts of Dalton's burial, to know that the mode adopted in this respect to do honour to his memory was a source of pain and offence to the members of that estimable religious body with which the deceased had always retained connexion. Who were to blame, if the thing is to be accounted as blame-worthy, for this ceremonial, we shall not stop to inquire. It is quite certain that the people of Manchester generally were actuated by no other feeling than that of an earnest desire to honour the illustrious dead: and there is something solemn and sublime in the idea of the intelligent thousands of a great city, forgetting for a time the claims of business, attiring themselves in the weeds of woe, and gathering round the bier of a solitary scientific recluse like Dalton. This feeling is heightened by the thought that it was no questionable hero, no noisy demagogue or destroyer of his species, to whom the multitude were doing this homage, but a true high-priest of nature, and a benefactor of his fellow-men.

In stature, Dalton was about the middle size, of strong rather than of elegant proportions. The likeness between his head and face and those of Newton was often observed during his lifetime, and is said to have become more striking after death. When engaged in study, a certain air of severity, such as may be seen on the busts of Newton, shadowed his features; but the gentle smile on his lips showed even the inexperienced physiognomist that it was deep thought, not angry passion, that wrinkled his brow.

Till his seventieth year he enjoyed robust health, and he was all his lifetime fond of exercise in the open air. He made a yearly journey to his native mountains of Cumberland and Westmoreland, and climbed Helvellyn, and often also Skiddaw. The afternoon of every Thursday he spent at a bowlinggreen, where he could join with some congenial associates in a turn at the old English game of bowls. We have heard a distinguished professor of chemistry tell that he once called for Dalton at his laboratory on a Thursday, and was directed to look for him at the bowling-green. Dalton quietly apologized for being out of his laboratory, adding that he liked to take a Saturday in the middle of the week. He was entitled to do so, as he

did not take one at the end, the seventh day being always a day of hard labour with him.

We have already alluded to a peculiarity in Dalton's vision, which he made the subject of the first paper he read to the Manchester Society in 1794. It consisted in this, that whereas most persons see seven colours in the solar spectrum, he saw only two-yellow and blue; or at most three-yellow, blue, and purple. He saw no difference between red and green, so that he thought the face of a laurel leaf a good match to a stick of red sealing'wax; and the back of the leaf answers to the lighter red of 'wafers.' When Professor Whewell asked him what he would compare his scarlet doctor's gown to, he pointed to the leaves of the trees around them. Dalton found nearly twenty persons possessed of the same peculiarity of vision as himself. The celebrated metaphysician, Dugald Stewart, was one of them, and could not distinguish a crimson fruit like the Siberian crab from the leaves of the tree on which it grew, otherwise than by the difference in its form.

This failure to perceive certain colours is by no means rare, and has excited a great deal of attention. The continental philosophers have named it Daltonism, a name which has been strongly objected to by almost every English writer who has discussed the subject, on the ground of the inexpediency and undesirableness of immortalizing the imperfections or personal peculiarities of celebrated men by titles of this kind. If this system of name-giving were once commenced, it is difficult to see where it would end. The possession of a stutter would be called Demosthenism; that of a crooked spine, Esopism; the lack of an arm, Nelsonism; and so on, till posterity would come to connect the names of our celebrated men, not with their superior gifts, or accomplishments, or achievements, but with the personal defects which distinguished them from their more favoured fellows.

Professor Whewell sought to better the matter by naming those circumstanced like Dalton, Idiopts, from two Greek words, signifying peculiarity of vision. But to this name it was justly objected by Sir David Brewster, that the important consonant p would be very apt to be omitted in hasty pronunciation, and so the last state of the Idiopt be worse than the first. Others have suggested various terms of Greek derivation, such as parachromatism, none of which, however, are sufficiently distinctive. The name Colour-Blindness,' proposed by Sir D. Brewster, seems in every respect unexceptionable.

*The reader who is curious in regard to this matter, will find a very elaborate article on the subject, entitled 'On Daltonism, or Colour- Blindness,' in the Scientific Memoirs,' an occasional periodical published by Richard Taylor, Red Lion Court, Fleet-street, London.

We are more concerned to know that Dalton supposed the peculiarity of his vision to depend upon the vitreous humour, (the liquid which fills up the greater part of the ball of the eye,) being in his case of a blue colour, instead of colourless, like water, as it is in the eyes of those who distinguish every tint. His own words are-It appears, therefore, almost beyond a 'doubt, that one of the humours of my eyes, and of the eyes of 'my fellows, is a coloured medium, probably some modification ' of blue. I suppose it must be the vitreous humour; otherwise I apprehend it might be discovered by inspection, which has 'not been done.'*

After Dalton's death, in obedience to his own instructions, his eyes were examined by his medical attendant, Mr. Ransome. The vitreous humour was not found, however, to present any blue tinge, but, on the other hand, was of a pale-yellow colour: neither did red and green objects looked at, through it, used as a lens, present any difference in tint to an ordinary eye, as they should have done had Dalton's hypothesis proved true. Were his view, indeed, the correct one, blue spectacles should induce the same peculiarity in the eyes of every one, which they are well known not to do. Everything, in truth, points to the cause of the colour-blindness, residing not in the optical apparatus of the eye, but in some peculiar condition of the brain or sensorium. So much for the physique of Dalton.

In endeavouring to form a conception of his mental peculiarities, we shall be assisted by comparing him with some of his great fellow-chemists. The labourers to whom chemistry has been indebted for its greatest advances admit of a natural division into two great classes. The one of these, and by far the smaller, contains men possessed of enthusiastic, imaginative, poetical temperaments, of sanguine, hopeful spirits, and great rapidity, subtlety and comprehensiveness of mind. Such preeminently was Davy; such is the great living chemist Liebig; and if we accept a very subtle fancy instead of a far-stretching imagination, such too was Priestley.

The other and larger class consists of men in whom the poetical element was at a minimum, who were characterized by great patience, self-concentration, and perseverance in thinking; for whom the working motto was, Non vi sed sæpe cadendo;' and in whom great self-possession and self-reliance were strongly developed, producing indifference to the opinion of others, and, in extreme cases, an almost repulsive hardness, sternness, and severity of character.

* Manchester Memoirs for 1798, p. 43.