important advantage was derived by Lamarck from the friendship of M. de Buffon. When the son of the latter had completed his studies, and was about to make a tour through various parts of Europe, Lamarck was invited to accompany him as tutor; and in order that he might enjoy greater privileges by appearing in a kind of official character, Buffon procured for him a commission as botanist to the king, for the purpose of visiting foreign gardens and cabinets, and opening a correspondence between them and similar establishments in Paris. In this double capacity he travelled through various countries in the year 1781 and 1782; visited Gleditsch at Berlin, Jacquin at Vienna, Murray at Gottingen, and many other celebrated naturalists; greatly extending his acquaintance, not only with botany, but with many other branches of natural history.
The extent and accuracy of his botanical knowledge was evinced by the important works in which he engaged shortly after his return, which have conferred on him a high reputation in this department. These consisted of voluminous contributions to the Encyclopédie Methodique, forming a Dictionary of Botany, and an extensive series of Illustrations of Genera. Of that portion of the Encyclopædia known by the former name, Lamarck wrote the whole of the two first volumes, and a part of the third, fourth, and fifth. The object of the work is to give a detailed history of plants, accompanied with descriptions, remarks on their synonymy, an account of their uses, and peculiarities of their structure. The Illustrations profess to afford “an exposition of the characters of all the plants established by botanists, arranged according to the sexual system of Linnæus, with figures displaying the characters of these genera, and a table of all the known species referable thereto, the description of which is found in the Botanical Dictionary of the Encyclopædia.” This laborious work contains no fewer than two thousand genera, illustrated by half that number of quarto plates, executed with great care, and generally representing one or two of the typical species, with a view to afford a knowledge of their general appearance and habit. The flower and parts of fructification are carefully delineated, and the precision and accuracy of the whole work, renders it one of the most valuable that can be named for conveying a speedy knowledge of the extensive and interesting subject of which it treats. The zeal with which Lamarck laboured to produce works of such research and interest, is characteristic of the temperament of his mind. He seems for a time to have allowed the subject wholly to engross his thoughts; to have occupied himself with nothing but plants, and to have associated almost exclusively with botanists. He was a frequent visitor at the house of M. de Jussieu, whose celebrity drew around him all who devoted themselves to this branch of science. Whenever a new collection of plants arrived in Paris, Lamarck was the first to inspect it; and when the celebrated Sonnerat returned from India in 1781, he was so much pleased with Lamarck’s enthusiasm, as contrasted with the comparative indifference of most other naturalists, that he presented him with the magnificent herbarium which he had made in the east. It is to zeal like this that we are entitled to look for the achievement of the highest results in science.
Notwithstanding the patronage of Buffon, and others having the greatest influence with the government, it was long before Lamarck succeeded in obtaining any permanent and lucrative appointment. His chief dependence was on the casual and precarious engagements which he formed with booksellers, according to whose direction he was obliged to labour; a painful restraint to a man of genius, impatient to develope his own conceptions in whatever way he judged best fitted to render them effective. He was at length nominated by M. de la Billardiere, a relation of his own, to a place which seems to have been created expressly for him, by which the duty was assigned him of keeping the herbaria in the king’s cabinet. Although the emolument arising from this office was inconsiderable, and the tenure of it uncertain and invidious, for the National Assembly were called upon to suppress it as unnecessary, he continued to hold it for several years, till a change occurred which opened new prospects and entailed new duties. This happened in 1793, when the establishment known by the name of the king’s garden and cabinet were remodelled and distinguished by the title of Museum of Natural History. The professors of the suppressed institution were appointed to superintend such departments taught in the new, as most nearly corresponded to their previous occupations; and as Lamarck was the last appointed, he was obliged to take charge of that branch unappropriated by the others, which happened to be the two extensive classes of the animal kingdom, named Insecta and Vermes by Linnæus.
A new direction was thus given to his studies, for zoology as a science had hitherto occupied but little of his regard. Indeed, the only knowledge of this subject which he possessed, directly available in his new station, seems to have been limited to Testaceous Mollusca, which attracted his attention at a pretty early period. But the occasion was just such a one as was best calculated to excite the natural ardour and energy of his character. He entered upon this new field of inquiry with the utmost eagerness, and cultivated it with so much skill and facility, that he was soon in a condition to instruct others, and ultimately to produce works which will form a lasting monument to his fame.
Before engaging in the study of practical zoology, Lamarck had rendered himself conspicuous by the boldness and originality of his speculations regarding a variety of physical phenomena. The general laws of chemistry, the origin of the globe and its inhabitants, the condition of the atmosphere and of living bodies, and most other great questions fitted to attract an active fancy, had by turns been the subjects of his contemplation; and on many of them he had elaborated a theory which he conceived calculated to elucidate the most abstruse phenomena they presented. To these views he attached the highest importance, considering them destined to place almost every branch of knowledge on a new and secure foundation. He therefore took advantage of every opportunity to enforce and illustrate them, and they will be found to pervade most of his published works, even such as afford no obvious plea for their introduction. Although most of them are exploded as fanciful and untenable, these theories display much ingenuity and extensive knowledge, and a pretty full account of them is necessary to show the character of Lamarck’s mind, and the wide range of his studies.
As early as 1780, he had presented his Theory of Chemistry to the Academy of Sciences; but it was not published for several years afterwards, when it appeared under the title of “Researches on the Causes of the most important physical Facts, and particularly on those of Combustion; of the raising of Water in the State of Vapour; of the Heat produced by the Friction of solid Bodies against each other,” &c. &c. A condensed view of the opinions promulgated in that work, and some others on the same subject, is thus given by Cuvier. According to our author, “Matter is not homogeneous; it consists of simple principles, essentially different among themselves. The connexion of these principles in compounds varies in intensity; they mutually conceal each other, more or less, according as each of them is more or less predominant. The principle of no compound is ever in a natural state, but always more or less modified: as, however, it is not agreeable to reason that a substance should have a tendency to depart from its natural condition, it must be concluded, that combinations are not produced by Nature, but that, on the contrary, she tends unceasingly to destroy the combinations which exist, and each principle of a compound body tries to disengage itself according to the degree of its energy. From this tendency, favoured by the presence of water, dissolutions result: affinities have no influence; and all experiments by which it is attempted to be proved that water decomposes, and consists of many kinds of air, are mere illusions, and that it is fire which produces them. The element of fire2 is subject, like the others, to modification when combined. In its natural state, everywhere diffused and penetrating every substance, it is absolutely imperceptible: only, when it is put in vibration, it becomes the essence of sound; for air is not the vehicle of sound as natural philosophers believe3. But fire is fixed in a great number of bodies, where it accumulates, and becomes, in its highest degree of condensation, carbonic fire, the basis of all combustible substances, and the cause of all colours. When less condensed, and more liable to escape, it is acidific fire (feu acidifique), the cause of causticity when in great abundance, and of tastes and smells when less so. At the moment when it disengages itself, and in its transitory state of expansive motion, it is caloric fire. It is in this form that it dilates, warms, liquifies, and volatilizes bodies by surrounding their molecules; that it burns them by destroying their aggregation; and that it calcines or acidifies them by again becoming fixed in them. In the
