and brevity of his observations, and set off to the greatest advantage the pleasant anecdotes which he delivered with the same grave brow and the same calm smile playing soberly on his lips. There was nothing of effort, indeed, or impatience, any more than of pride or levity, in his demeanour; and there was a finer expression of reposing strength, and mild selfpossession in his manner, than we ever recollect to have met with in any other person. He had in his character the utmost abhorrence for all sorts of forwardness, parade, and pretension; and, indeed, never failed to put all such impostors out of countenance, by the manly plainness and honest intrepidity of his language and deportment.

In his temper and dispositions he was not only kind and affectionate, but generous, and considerate of the feelings of all around him, and gave the most liberal assistance and encouragement to all young persons who shewed any indications of talent, or applied to him for patronage or advice. His health, which was delicate from his youth upwards, seemed to become firmer as he advanced in years; and he preserved, up almost to the last moment of his existence, not only the full command of his extraordinary intellect, but all the alacrity of spirit, and the social gaiety which had illuminated his happiest days. His friends in this part of the country never saw him more full of intellectual vigour and colloquial animation,-never more delightful or more instructive than in his last visit to Scotland in autumn 1817. Indeed, it was after that time that he applied himself, with all the ardour of early life, to the invention of a machine for mechanically copying all sorts of sculpture and statuary,―and distributed among his friends some of its earliest performances, as the productions of a young artist just entering on his 83d year.

This happy and useful life came at last to a gentle close. He had suffered some inconvenience through the summer; but was not seriously indisposed till within a few weeks from his death. He then became perfectly aware of the event which was approaching; and with his usual tranquillity and benevolence of nature, seemed only anxious to point out to the friends around him the many sources of consolation which were afforded by the circumstances under which it was about to take place. He expressed his sincere gratitude to Providence for the length of days with which he had been blessed, and his exemption from most of the in

firmities of age, as well as for the calm and cheerful evening of life that he had been permitted to enjoy, after the honourable labours of the day had been concluded. And thus, full of years and honours, in all calmness and tranquillity, he yielded up his soul, without pang or struggle,— and passed from the bosom of his family to that of his God.

He was twice married, but has left no issue but one son, long associated with him in his business and studies, and two grandchildren by a daughter who predeceased him. He was a Fellow of the Royal Societies both of London and Edinburgh, and one of the few Englishmen who were elected members of the National Institute of France. All men of learning and science were his cordial friends; and such was the influence of his mild character and perfect fairness and liberality, even upon the pretenders to these accomplishments, that he lived to disarm even envy itself, and died, we verily believe, without a single enemy.

HISTORICAL ACCOUNT

OF THE

DISCOVERY OF THE COMPOSITION OF WATER.

BY THE

RIGHT HON. HENRY LORD BROUGHAM,

F. R. S., AND MEMBER OF THE NATIONAL INSTITUTE OF FRANCE.

THERE can be no doubt whatever that the experiment of Mr Warltire,* related in Dr Priestley's 5th volume, gave rise to this inquiry, at least in England; Mr Cavendish expressly refers to it, as having set him upon making his experiments.-(Phil. Trans. 1784, p. 126.) The experiment of Mr Warltire consisted in firing by electricity a mixture of inflammable and common air in a close vessel, and two things were said to be observed; first, A sensible loss of weight; second, A dewy deposit on the sides of the vessel.

Mr Watt, in a note to p. 332 of his paper, Phil. Trans. 1784, inadvertently states, that the dewy deposit was first observed by Mr Cavendish ;

* Mr Warltire's letter is dated Birmingham, 18th April 1781, and was published by Dr Priestley in the Appendix to the 2d Vol. of his " Experiments and Observations relating to various branches of Natural Philosophy; with a continuation of the Observations on Air,”—forming in fact the 5th volume of his “Experiments and Observations on different kinds of Air," printed at Birmingham in 1781.

Mr

but Mr Cavendish himself, p. 127, expressly states Mr Warltire to have observed it, and cites Dr Priestley's 5th volume.

Mr Cavendish himself could find no loss of weight, and he says that Dr Priestley had also tried the experiment, and found none. But Mr Cavendish found there was always a dewy deposit, without any sooty matter. The result of many trials was, that common air and inflammable

Mr Warltire's first experiments were made in a copper ball or flask, which held three wine pints, the weight 14 oz.; and his object was to determine “whether heat is heavy or not." After stating his mode of mixing the airs, and of adjusting the balance, he says he "always accurately balanced the flask of common air, then found the difference of weight after the inflammable air was introduced, that he might be certain he had confined the proper proportion of each. The electric spark having passed through them, the flask became hot, and was cooled by exposing it to the common air of the room: it was then hung up again to the balance, and a loss of weight was always found, but not constantly the same; upon an average it was two grains."

He goes on to say, "I have fired air in glass vessels, since I saw you (Dr Priestley) venture to do it, and I have observed, as you did, that, though the glass was clean and dry before, yet, after firing the air, it became dewy, and was lined with a sooty substance."

As you are upon a nice balancing of claims, ought not Dr Priestley to have the credit of first noticing the dew?

In some remarks which follow by Dr Priestley, he confirms the loss of weight, and adds, "I do not think, however, that so very bold an opinion, as that of the latent heat of bodies contributing to their weight, should be received without more experiments, and made upon a still larger scale. If it be confirmed, it will no doubt be thought to be a fact of a very remarkable nature, and will do the greatest honour to the sagacity of Mr Warltire. I must add, that the moment he saw the moisture on the inside of the close glass vessel in which I afterwards fired the inflammable air, he said, that it confirmed an opinion had he long entertained, viz. that common air deposits its moisture when it is dephlogisticated."

It seems evident, that neither Mr Warltire, nor Dr Priestley, attributed the dew to any thing else than a mechanical deposit of the moisture suspended in common air. (NOTE BY MR JAMES WATT.)

Mr Cavendish's note, p. 127, would seem to imply this; but I have not found in any of Dr Priestley's papers that he has said so.-(NOTE BY Mr JAMES WATT.)

air being burnt together, in the proportion of 1000 measures of the former to 423 of the latter," about one-fifth of the common air, and nearly all the inflammable air, lose their elasticity, and are condensed into the dew which lines the glass." He examined the dew, and found it to be pure water. He therefore concludes, that " almost all the inflammable air, and about one-sixth of the common air, are turned into pure water."

Mr Cavendish then burned in the same way dephlogisticated and inflammable airs (oxygen and hydrogen gases), and the deposit was always more or less acidulous, accordingly as the air burnt with the inflammable air was more or less phlogisticated. The acid was found to be nitrous. Mr Cavendish states, that "almost the whole of the inflammable and dephlogisticated air is converted into pure water." And, again, that "if these airs could be obtained perfectly pure, the whole would be condensed." And he accounts for common air and inflammable air when burnt together not producing acid, by supposing that the heat produced is not sufficient. He then says that these experiments, with the exception of what relates to the acid, were made in the summer of 1781, and mentioned to Dr Priestley, and adds, that "a friend of his (Mr Cavendish's) last summer (that is 1783) gave some account of them to Mr Lavoisier, as well as of the conclusion drawn from them, that dephlogisticated air is only water deprived of its phlogiston; but at that time so far was Mr Lavoisier from thinking any such opinion warranted, that till he was prevailed upon to repeat the experiment himself, he found some difficulty in believing that nearly the whole of the two airs could be converted into water." The friend is known to have been Dr, afterwards Sir Charles Blagden; and it is a remarkable circumstance, that this passage of Mr Cavendish's paper appears not to have been in it when originally presented to the Royal Society, for the paper is apparently in Mr Cavendish's hand, and the paragraph p. 134, 135, is not found in it, but is added to it, and directed to be inserted in that place. It is moreover not in Mr Cavendish's hand, but in Sir Charles Blagden's, and indeed the latter must have given him the information as to Mr Lavoisier, with whom it is not said that Mr Cavendish had any correspondence. The paper itself was read 15th January 1784. The volume was published about six months afterwards.

Mr Lavoisier's memoir (in the Mem. of the Académie des Sciences for