differences of the substances that were before him, it was by no means a matter of little moment in his estimation, whether the pounding which was always continued till the body was reduced to an impalpable powder was conducted in vessels of flint, of calcedony, of glass, of serpentine, or of metal. And when he operated with fire, he always selected his vessels, whether of earthen-ware, of glass, of graphite, of iron, of silver, or of platina, upon fixed principles, and showed more distinctly than chemists had previously been aware, what an effect the vessel often has upon the result. Not less important was the extreme care which he used in preparing pure reagents, for obtaining which in their most perfect state, he invented several efficient methods.

It

Nor must we pass unnoticed his scientific manner, both in oral delivery and in composition. His language was simple and unadorned, but clear, well defined, and condensed. He never used more words than were absolutely necessary for a complete elucidation of the matter in hand. He rather pointed out than entered into any discursive exhibition of the grounds of his operations,-in general, he employed few reasonings, and only a simple statement of the essential circumstances of an experiment and of its consequences. was particularly remarkable in him, however, that neither in his oral communications, nor in writing, neither in plain words nor by hints, did he ever attempt to exalt his own discoveries, or to bring them nearer either to the eye or the ear of his hearers. His pupils never heard from his own mouth how much science had been indebted to him, so utterly averse was he to all vanity, all boasting, and all selfishness. In a word, truth and science were every thing with him; the moment these began to occupy him, every other interest was hushed, and passed into the back ground.

The essays which he has given to the public, with a few exceptions, contain analyses of inorganic bodies. But it would be a mistake to infer from this, that his chemical knowledge was of a partial nature. It is quite natural, that a man of excellent talents should devote himself with a preference to that particular field in which his first attempts had been followed by distinguished results, where he had found many weeds to root out, much space to be planted anew, and a great deal of uncultivated ground to be rendered productive. But he is not likely to have accomplished any thing remarkable, even in that department which he had chosen for himself, nor any thing that has a relation to the whole science, unless he is thoroughly acquainted with all its

parts. Every science is a great and intimately connected whole, no part of which can be cultivated with any important result in an isolated state. It is true that a person of a peculiar taste, may attach himself to one part of a science which, in its entire extent, is unknown to him, and in that single department may make many discoveries, as Franklin in electricity, or may make some fine observations, as was done by Göthe, in regard to colours. But, in such instances, the person must be at the greatest loss for proper means of estimating causes, both in the material and intellectual world, -he must be constantly exposed to the danger of mistaking what is insignificant for what is important,-what is great. for what is superfluous,-truth for error, and error for truth; in short, his labours cannot have that completely solid result which attended those of Klaproth. Those who knew him intimately, are aware that he kept fully up with the progress of his age, and that nothing which was important within the dominions of his science escaped his notice.

was not satisfied with merely reading and understanding what had been done by others; he repeated every new experiment, to whatever department of his science it might belong, to convince himself of the correctness of the facts that were announced. How susceptible he was of the impression of new views, was distinctly seen at the time of the antiphlogistic chemistry, when, with the utmost alacrity, he overturned his whole previous system, the moment he was convinced, by a careful repetition of the experiments, of the correctness of the facts on which Lavoisier had founded his new doctrines. Even in his advanced years, he did not tenaciously adhere to his old views. In early life he had adopted, like all other chemists, the doctrine of affinities proposed by Bergmann, as the foundation of his explanations, although he took many opportunities of warning those who attended his lectures respecting its insufficiency. When Berthollet's investigations, respecting the laws of affinity appeared, he completely satisfied himself of the untenable nature of his former views; and although he did not think that, in regard to several particulars, he could assent to the decision of the ingenious French chemists, he was yet perfectly satisfied as to the correctness of the principle on which all the investigations of Berthollet proceed, namely, that no one power is adequate to the explanation of chemical phenomena, but that, even in the case of the simplest composition or resolution, several powers unite their energies. He also admitted the necessary consequence of this principle, namely, that

it is impossible to arrive at a true scientific theory in chemistry in any other way, but by the most careful consideration and investigation of the laws, according to which the individual active powers and circumstances, that is to say, the powers of cohesion and of expansion, fluidity, gravitation, quantity, heat, light, electricity, and so forth, produce their effect. Klaproth perceived that those only who were conducted as by the hand by the presiding deity of the mathematics, could make any considerable advances in the path which Berthollet had opened upon; and he was hence sorry that his defective education when at school had permitted him only to obtain a very superficial acquaintance with that science, in which with better opportunities, he would unquestionably have made considerable progress, since, even without the aid of that science, he had been able to appropriate to himself, in a very high degree, the exactness and solidity of the mathematical talent. The value which he put, in general, upon the views of Berthollet, was the motive which induced him to encourage the author of this memoir to translate Berthollet's investigations into the language of Germany. But, however little reason the translator might have to be dissatisfied with the reception which his labours gained with the literary public, it is impossible for him to conceal from himself, that they have never yet completely attained the end proposed by them. It would not be difficult to explain the causes of this. They are to be found partly in some unfavourable accidents,-partly in certain peculiarities of the age, which are not very propitious to deep scientific study. But a more detailed explanation of these circumstances is foreign to the purpose of this memoir. The author contents himself, therefore, with adding, that, without making any pretensions to the gift of prophecy, he may venture to assert, that, sooner or later, the sound principles of Berthollet must be had recourse to, if ever chemistry is to be placed on a more scientific foundation.

Even at an advanced period of life, Klaproth changed his early views in regard to many objects, as, for instance, with respect to the problematic body, named Muriatic Acid; with respect to the impossibility of decomposing the alkalies and earths, and several other points; and by these changes of opinion, he shewed, that even advanced years had not deprived him of the power of being struck by new views and ideas. With so many distinguished scientific claims, it is not to be wondered, that all the learned societies in Europe, whose object was in any way connected with physical science,

should have reckoned it an honour to have the name of so illustrious a man in the list of their members. Besides the two Academies of Science and of Arts in Berlin, he was also a member of the Academies of Paris, London, Petersburg, Stockholm, Copenhagen, and Munich, and of many associations of learned men at Edinburgh, Berlin, Paris, Moscow, Brussels, Erfurt, Halle, Erlangen, Jena, Potsdam, Leipsic, Hamm, Rostock, and other places. Among his papers, there was found, after his death, not less than thirty diplomas from learned societies; and the king (of Prussia) added to these honours, in the year 1811, the order of the Red Eagle of the Third Class.

The State too, in acknowledgment of Klaproth's merits, rewarded his industry in a variety of ways. So far back as the year 1782, he had been Assessor in the Supreme College of Medicine and of Health, which then existed; at a more recent period, he enjoyed the same rank in the Supreme Council of Medicine and of Health: and when this College was subverted in 1810, he became a member of the Medical Deputation attached to the Ministry of the Interior. He was also a member of the Perpetual Court Commission for Medicines. His lectures, too, procured for him several municipal situations. For as soon as the public became acquainted with his great chemical acquirements, he was permitted to give yearly, two private courses of lectures on chemistry, one for the officers of the Royal Artillery Corps, the other for persons not connected with the army, who wished to accomplish themselves for some practical employment. Both of these lectures assumed afterwards a municipal character. The former led to his appointment as Professor of the Artillery Academy, instituted at Tempelhoff, and after its dissolution to his situation as Professor in the Royal War School. The other lecture procured for him the Professorship of Chemistry in the Royal Mining Institute. On the establishment of the present University, Klaproth's lectures became those of the University, and he himself was appointed ordinary Professor of Chemistry, and a member of the Academical Senate. Besides these public lectures, our departed friend was an active member from 1797 to 1810, of a small scientific society, which met yearly during a few weeks, for the purpose of discussing the more recondite mysteries of the science, and of which all the members still retain lively recollections.

I cannot resist the inclination which I feel to repeat in this place, a remark which Klaproth used to make respecting his prelections, and which he repeated more than once to the

author of this memoir, as well as to several other friends. As long as his lectures were honoured by the presence of students only, they were numerously attended and earnestly listened to; but when the State began to pay for a part of the students, a considerable number of these began forthwith to take a very irregular and diminished interest in the lectures. It is certainly exceedingly proper that the State should take an interest in the scientific accomplishment of its subjects, by the erection of schools of different kinds; and it is still more proper, that it should afford to those who have not the means, the possibility of an enlightened education; but, perhaps, it would be most desirable in cases of this kind, not to release any of the scholars from the duty of paying for instruction, but rather to assist the needy, by furnishing them from a particular source, with the fees, which all should be bound to pay.

In an attempt to do justice to the merits of Klaproth, I cannot altogether pass over one part of them, which might readily remain unnoticed by the public, although it deserves to be generally known,-I speak of the great and beneficial influence which Klaproth, along with several other very respectable men, had upon Free-Masonry. It has not escaped the notice of the public, that during the preceding century all sorts of fooleries, alchemy, ghost-seeing, Rosicrucian enthusiasm, and many other things of the same kind, had crept into Free-Masonry. But their influence, although for a time it turned many heads, could neither be long continued nor of extensive operation; because within the society itself there were always men who laboured to counteract those errors, and Klaproth in particular was one of those respectable men who earnestly and powerfully waged war with deceptions of that kind, who endeavoured to expose it in all its insignificance, and tried to bring back those who had erred into the right way. How much he was assisted in this office by his profound acquaintance with the science of Nature, and by his incorruptible integrity; and how well he has deserved by his labours not only of science, but of the human race, must be evident to every unprejudiced person who has but a moderate acquaintance with the intricate connexions of human affairs.

In the preceding remarks, I have noticed many honourable characteristics of this excellent man, and shall feel happy, if, in concluding this memoir, I could present you with a likeness of him.