MICHAEL, a celebrated naturalist, was descended from a Scottish family which had at the Revolution attached itself to the fortunes of the house of Stuart; and was born the 7th of April 1727, at Aix in Provence, where his father was in the service of M. de Vintimille, then archbishop of that province. On the translation of this prelate to the archbishopric of Paris, about the year 1730, the elder Adansons also repaired thither, accompanied by his infant family of five children, all of whom were provided for by their father's patron. A small canonry fell to the lot of our future naturalist, the revenue of which defrayed the expenses of his education at the college of Plessis. While there, he was distinguished for great quickness of apprehension, strength of memory, and mental ardour; but his genius took no particular bent, until he received a microscope from the celebrated Tuberville Needham, who happened to be present at one of the public examinations, and was struck with admiration of his talents and acquirements. From the moment that young Adanson received this donation, to the last hour of his life, he persevered with a zeal almost unexampled, in the observation and study of nature.

On leaving college, his youthful ardour was well employed in the cabinets of Reaumur and Bernard de Jussieu, as well as in the Jardin des Plantes. Such was his zeal, that he repeated the instructions of the professors to such of his fellow-students as could not advance with a rapidity equal to his own; and before he had completed his nineteenth year, he had actually described (for his own improvement) four thousand species of the three kingdoms of nature. In this way he soon exhausted the rich stores of accumulated knowledge in Europe; and having obtained a small appointment in the colony of Senegal, he resigned his canonry, and embarked on the 20th of December 1748 for Africa.

The motives which decided the choice of Senegal as the scene of his observations are recorded by himself, and are too remarkably indicative of his ardent thirst of knowledge not to be noticed. "It was," says he, in a memorandum found after his death, "of all European establishments the most difficult to penetrate, the most hot, the most unhealthy, the most dangerous in every respect, and consequently the least known to naturalists."

His ardour remained unabated during the five years that he remained in Africa, in which period he collected and described an immense number of animals and plants; delineated maps of the country, and made astronomical observations; prepared grammars and dictionaries of the languages spoken on the banks of the Senegal; kept meteorological registers; composed a detailed account of all the plants of the country; and collected specimens of every object of commerce. M. Cuvier mentions that he had seen the produce and results of all these multifarious and laborious exertions.

He founded his classification of all known organized beings Adanson, on the consideration of each individual organ. As each organ gave birth to new relations, so he established a corresponding number of arbitrary arrangements. Those beings possessing the greatest number of similar organs were referred to one great division, and the relationship was considered more remote in proportion to the dissimilarity of organs.

The chief defect of this method consists in presupposing a knowledge of species and their organization, altogether beyond the existing stage of attainment. It gives, however, distinct ideas of the degree of affinity subsisting between organized beings, independent of all physiological science. Of this universal method, as he called it, Adanson gave some account in an essay contained in his Treatise on Shells, published at the end of his Voyage au Sénégal.

Until the appearance of this work, the animals inhabiting shells had been much neglected. On this branch of his subject our author exercised his wonted zeal, while his methodical distribution, founded on not less than twenty of the partial classifications already alluded to, is decidedly superior to that of any of his predecessors. Like every first attempt, however, it had its imperfections, and these arose from not having examined the anatomical structure of the animals; from which cause he omitted, in his arrangement of the class of Mollusca, all molluscous animals without shells.

His original plan was to have published the whole of the observations made during his residence at Senegal, in eight volumes; but being deterred by the difficulties attending so extensive a publication, he abandoned the scheme, and applied himself entirely to his Families of Plants, which he published in 1763. In this he found the application of his general principle not less advantageous than in his preceding works.

In 1774 (eleven years after the appearance of his Families of Plants), he submitted to the consideration of the Academy of Sciences an immense work, containing what may be called the universal application of his universal method; for it extended to all known beings and substances, whether in the heavens or on the earth. Twenty-seven large volumes of manuscripts were employed in displaying the general relations of all these matters, and their distribution. One hundred and fifty volumes more were occupied with the alphabetical arrangement of 40,000 species. There was also a vocabulary, which contained 200,000 words, with their explanations; and the whole was closed by a number of detached memoirs, 40,000 figures, and 30,000 specimens of the three kingdoms of nature. The committee of the academy to which the inspection of this enormous mass had been intrusted, warmly recommended to Adanson to separate and publish all that was peculiarly his own, leaving out what was merely compilation; but he obstinately rejected this reasonable advice; by which means science has been deprived of many essays, which, if we may judge from others which he at different times gave to the world, would have possessed great merit. But his life was now drawing near to its close. He died, after many months of severe suffering, on the 3d of August 1806.

Adanson was never married. In his will he requested, as the only decoration of his grave, a garland of flowers gathered from the fifty-eight families which he had established—“a touching though transitory image,” says Cuvier, “of the more durable monument which he has erected to himself in his works.” His zeal for science, his unwearied industry, and his talents as a philosophical observer, are conspicuous in all his writings. The serenity of his temper, and the unaffected goodness of his heart, endeared him to the few who knew him intimately.

His most important works are, his Voyage to Senegal, and his Families of Plants. To the former some essays, already noticed, were subjoined; and various others were published, at different times, in the Transactions of the Academy of Sciences. The volumes for the years 1759 and 1761 contain his observations upon the Taret, (a species of shell-fish exceedingly destructive to vessels,) and his account of the Baobab, an enormous African tree, now known under the name of Adansonia. The volume for 1769 contains an interesting discussion by Adanson, upon the origin of the varieties of cultivated plants; and in those for 1773 and 1779 will be found his valuable observations on gum-bearing trees. In the Transactions of 1767 he gave an account of the Oscillatoria Adansoni, which he considered a self-moving vegetable; but which ought, according to some observations of M. Vaucher, to be ranked as a zoophyte. Besides these essays, Adanson contributed several valuable articles in natural history to the earlier part of the Supplement to the first Encyclopédie; and he is also supposed to have been the author of an essay on the Electricity of the Tourmaline (Paris 1757), which bears the name of the Duke of Noval Caraffa. See Eloge Historique de M. Adanson, par Cuvier; Mémoires Mathématiques et Physiques de l'Inst. National, tom. vii.