I think, would upon no event become so, viz., the legacy of two hundred pounds sterling. I hereby therefore discharge it for ever; and least this discharge should be lost, I shall be careful to mention it in a note at the bottom of my will. I shall be glad to hear that you have received this letter, and hope you will believe me to be, both on your brother's account and your own, with great truth, most affectionately,

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Yours,

"ADAM SMITH.

"P.S.-I do not hereby mean to discharge the other legacy, viz., that of a copy of his works."

"DEAR SIR,

"EDINBURGH, September 2nd, 1776.

"I was favoured with your's of Saturday, and I assure you that, on perusing the destinations, I was more of opinion than when I saw you, that the pecuniary part of it was not altered by the codicil, and that it was intended for you at all events; that my brother knowing your liberal way of thinking, laid on you something as an equivalent, not imagining you would refuse a small gratuity from the funds it was to come from, as a testimony of his friendship; and though I must highly esteem the motives and manner, I cannot agree to accept of your renunciation, but leave you full master to dispose of it which way is most agreeable to you.

"The copys of the Dialogues are finished, and of the Life, and will be sent to Mr. Strahan to-morrow; and I will mention to him your intention of adding to the last something to finish so valuable a life, and will leave you at Liberty to look into the correction of the first, as it either answers your leisure or ideas with regard to the composition, or what effects you think it may have with regard to yourself. The two copys intended for you will be left with my sister, when you please to require them; and the copy of the new edition of his works you shall be sure to receive, though you have no better title to that part than the other, though much you have to the friendship and esteem of, Dear Sir, him who is most sincerely,

LAVOISIER.

In the Lives of Black, Priestley, Watt, and Cavendish, it has been necessary to mention the claims of Lavoisier, first as a competitor with the great philosophers of the age for the honour of their discoveries, yet as an intruder among them by his attempts to show that he had himself, though unknown to them and ignorant of their inquiries, made the same steps nearly at the same time. The history of that great man, which we are now to consider, will enable us to perceive clearly the evidence upon which the charge rests, both the proof of his having preferred those claims, and the proof that they were groundless. But it will also enable us to perceive how vast his real merits were, and how much remained his own of the discoveries which have built up the science of modern chemistry, even after all those plumes have been stript away that belonged to others.

It is a very great error to suppose that the truths of philosophy are alone important to be learnt by its students; that provided these truths are taught, it signifies little when or by whom or by what steps they were discovered. The history of science, of the stages by which its advances have been made, of the relative merits by which each of our teachers was successively made famous, is of an importance far beyond its being subservient to the gratification even of an enlightened and learned curiosity. It is eminently calculated to further the progress which it records; it conveys peculiarly clear and discriminating ideas upon the doctrines taught, and the proofs they rest on; it suggests new inquiries, and encourages the prosecuting of new re

searches. It is, moreover, both a debt of gratitude to our benefactors which we should be anxious to pay by testifying our gratitude, and commemorating their fame; and the discharge of this duty has a direct tendency to excite emulation, prompting to further labours that may enlarge the bounds of science. Besides, the history of scientific achievements is the history of the human mind in its noblest exertions, of the human race in its most exalted pursuits. But it is equally clear that the whole value of this, as of every other branch of history, depends upon the diligence with which the facts are examined, the care and even the skill with which their evidence is sifted, the impartiality with which judgment is pronounced, and the accuracy with which the record is finally made up. The mere panegyric of eminent men, how elegantly soever it may be composed, must remain wholly worthless, at the best, and is capable of being mischievous, if it aims at praise without due discrimination, still more if it awards to one man the eulogy which of right belongs to another. Nothing can be more indispensable to the execution of the important task undertaken by the historian of science, than that he should most carefully examine the share which each of its cultivators had in the successive changes it has undergone. The greatest of these have ever felt how valuable such titles are, and have shown the most singular anxiety to compare and to adjust their relative claims. Of these illustrious men I have known two, Black and Watt, and I can safely say that when the question was raised of priority in discovery among either their predecessors or their cotemporaries, they were wont to be particular and minute, even to what seemed superfluous carefulness, in assigning to each his just share, very far more anxious in making this distribution than they ever showed themselves to secure the admission of their titles in their own case. By a singular injustice of fortune these two philosophers have themselves

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been treated with a more scanty measure of the like justice than perhaps any of their cotemporary discoverers. It is proposed to examine with the same minuteness the particulars in M. Lavoisier's history, upon which some controversy has at different times arisen.

Antoine Laurent Lavoisier was born at Paris, 13th of August, 1743, the son of an opulent family, his father having been a fermier-général. No expense was spared upon his education; and in the college of Mazarin, where he studied, he gained many prizes for proficiency in classical acquirements. It was, however, to the sciences that he soon devoted himself, and first to the severer ones, having made considerable proficiency in the mathematics and astronomy under La Caille, in whose observatory he studied upon leaving the college. He studied botany under Jussieu, and chemistry under Rouelle. As from his earliest years he appears to have been wholly consecrated to scientific pursuits, so no one ever entered upon his course with a more fervid courage. The earliest of his inquiries of which we have any knowledge was an analysis of gypsum, presented to the Academy of Sciences in 1765, and published in the collection of 'Mémoires de divers Savans,' 1768. In 1764 a prize had been proposed by M. de Sartine, the celebrated chief of the police of Paris, for the best method of lighting a great town, so as to combine illumination with economy, and with facility of service. After the lapse of twelve months no dissertation had been presented which satisfied the conditions of the programme, and the prize was doubled, being raised to 2000 livres; and next year, 1766, the conditions remaining still unsatisfied by the candidates, the prize was divided

* When any reference is made to the Eloges of the French Academy, justice requires me to add that those of M. Arago form a most striking exception. They are strictly historical, as well as philosophical. That of Watt is a model.

among the three best, while a Memoir of great merit, by M. Lavoisier, was honourably mentioned and ordered to be printed. The King, too, on M. de Sartine's recommendation, directed a gold medal to be bestowed upon the author, who was presented with it at the public sitting of the Academy in April, 1766. In 1769 he obtained the place of a fermier-général, by a kind of hereditary title; and in 1771 he married Marie-Anne Paulze, whose father likewise belonged to the same financial class. In 1768 he had been admitted a member of the Academy, at the early age of twenty-five. His paper on the lapis specularis, related to the composition of the great strata forming the basin of Paris.

He appears for some years to have occupied himself principally with geological inquiries; he made mineralogical journeys in various parts of France in company with M. Guettard; and he had collected materials for an extensive work on the revolutions of the globe, when the recent progress of another science gave a new direction to his pursuits. His paper on gypsum contains a number of experiments, which show it to be a neutral salt, soluble in a great proportion of water, and composed of sulphuric acid united to a calcareous base. This and almost every other position in his paper was well known before. M. Montigny had, in the Memoirs of the Academy,' 1762, shown its solubility, and M. Margraaff, in the 'Berlin Memoirs,' as far back as 1750, had proved both this and its composition. M. Lavoisier refers to these long-published works in a note appended to his paper, but states that he had not seen Margraaff's till after his own was read before the Academy. He also states that M. Baumè had published researches similar to his in a journal, but that he was not aware of this till he had made considerable progress with his paper. It is unfortunate that this eminent person should have begun his works with this kind of doubt hanging over his origi

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