CHARLES, an eminent naturalist, was born at Geneva on the 13th March 1720, of a French family who had been forced on account of religious principles to leave their native country. As he was an only son, his father paid great attention to his education; and finding that he made little progress at the public schools, both from a dislike to the dry study of grammar, and from deafness, with which he was very early afflicted, employed a domestic tutor, under whom his progress was rapid and satisfactory. At the early age of sixteen his attention was so deeply engaged by the perusal and study of Le Spectacle de la Nature of Pluche, that it seems to have given a bias and direction to his future studies. The history and the habits of the ant-lion, formica leo, particularly attracted his attention, and led him to make his first observations on natural history. He discovered the haunts of this curious insect, watched and studied its manners and habits, and added many observations to those of Pluche and Reaumur. Reaumur's memoir on insects happening to fall accidentally in his way, he perused it with great eagerness; and this perusal probably decided his taste for natural history. To the observations and experiments of that naturalist, Bonnet added many new facts which he had discovered, the detail of which he communicated to Reaumur; who was not less surprised than pleased to find so much sagacity and acuteness of research exhibited in the investigations of a young man of eighteen.

Bonnet had been destined by his father for the profession of the law; but it was with no small reluctance that he entered on the studies necessary to qualify himself for that profession. The bias of his mind leaned too strongly to natural history, to permit him to occupy his attention with other pursuits. The study of some of the elementary books on law was therefore submitted to merely as a task. In the years 1738 and 1739 he sent to Reaumur many interesting observations on different species of caterpillars; and in 1740 he communicated a paper to the Academy of Sciences respecting the propagation or multiplication of aphides, or tree-lice, without actual conjunction. This question had been left unsettled by Reaumur. It was now determined by decisive experiments; and his paper on the subject obtained for him the honour of being admitted a corresponding member of the Academy. His experiments on the generation of these insects were conducted with such closeness of attention, and such minuteness of research, as to injure his eyesight to such a degree that he never afterwards wholly recovered it. In the year 1741 he instituted a set of experiments on the effects that follow the division of worms; and he found that many species possessed in some degree the same reproductive power as the polypus. In the following year his investigations and experiments were directed to the peculiarities in the mode of respiration of caterpillars and butterflies; and he proved that this function was performed by means of pores, to which the name of stigma has been given. It was about the same time that he made some curious discoveries respecting the tenia, or tape-worm. In the year 1743, when he was raised to the rank of doctor of laws, he procured a ready dispensation from the further prosecution of studies which had never been agreeable to him, and which being no longer absolutely necessary, he relinquished for ever. In consequence of a memoir on insects which he commu- nicated to the Royal Society of London, the same year, he was admitted a member of that body. Next year he published, in one work, his observations on aphides and worms, under the title of *Insectology*. To this work he prefixed a preface, in which he exhibits a philosophical sketch of his ideas concerning the system of the development of germs, and the scale of organized beings. This work was in general well received by the public, but by some of the journals it was taxed with a want of delicacy, which, it was alleged, appeared in his descriptions of the mode of propagation of tree-lice.

The constant labours to which Bonnet had subjected himself in all his inquiries began to produce very serious consequences to his health. His eyes particularly began to be affected with severe pains, and his general health visibly declined. This not only obliged him to lay aside the use of the microscope, but also to forego for a time all reading and writing. But like a true philosopher, he bore his afflictions with patience. He was not idle; for although he was interdicted from all observation, his mind was fully occupied in reflection. After some time of relaxation from his usual pursuits, he was at last restored to tolerable health; but he never could employ his eyes with the same freedom as formerly. About the year 1746 he undertook a course of experiments on the vegetation of plants in moss and other substances; and in the following year his researches were directed to the functions of the leaves of plants, with the view of ascertaining the different action of the different sides of the leaves. Another question in vegetation offered itself to his consideration. This was the ascent of the sap—and to determine whether it rose by the bark or wood, he employed coloured injections. This investigation, with some observations which he made on vegetable monsters, was the foundation of one of his most interesting and original works, entitled "Inquiries into the use of the Leaves of Plants," which was first published at Leyden in 1754, 4to. A supplement was added to it in the year 1779.

Observation and experiment had been the first passion of Bonnet; yet these now began to give way to speculation; and his inquiries in natural history, in the course of which he had so much studied the nature and generation of the lowest part of the scale of beings, led him to consider the faculties and destination of the highest. Malebranche and Leibnitz had laid the foundation of his metaphysical ideas. He engaged deeply in all the discussions connected with the history of the human mind; and the first fruit of his meditations was a kind of abridgment of the materials he had collected, under the title of an "Essay on Pachylogy," published in London in 1754, but without his name, nor did he acknowledge it till nearly thirty years afterwards. This work contains, in a concise form, the fundamental principles of his philosophy. It traces the origin and progress of the human mind, from the first germ of life to the development of all its faculties, the mutual dependence of which it points out, as deduced from actual observation. It enters into the difficult subject of human liberty, and endeavours to reconcile it with the divine prescience, and the philosophical principle, that every effect must have an adequate cause. From the essential properties of the activity of the soul, and the effects of habit upon it, the whole art of education and government is deduced; and a system of the former is laid down, materially different from the methods generally established. The freedom with which he discussed some of these delicate points, and the fear of being involved in personal controversy, were the motives which induced the author to remain so long concealed. The work met with some censure, yet its success was brilliant.

The next work of Bonnet was a development of part of the subject of the preceding, namely, the origin and progress of the mental faculties. After a labour of five years on the subject, he produced his "Analytical Essay on the Faculties of the Soul," which was first printed at Copenhagen in 1760, in quarto, at the expense of the king of Denmark. In this work, like that of the Abbé Condillac, he supposes a statue organized like the human body, which he degrees animates, and shows how its ideas would arise from impressions on the organs of sense. The Analytical Essay was well received by philosophers, though among some it subjected him to a charge of materialism. To these he made no reply, but contented himself with proceeding in those efforts for the service of religion and morals, to which the best part of his life had been devoted. His retired and studious habits, together with his deafness and other bodily infirmities, prevented him from joining in the assemblies of the young and gay, at the same time that they rendered domestic comforts more essential to him. In 1758, he married a lady of the respectable family of De la Rive, and with her he passed thirty-seven years in that perfect union which results from mutual tenderness directed by good sense and virtue. The celebrated Saussure was the nephew of Madame Bonnet; and it was no small pleasure to her husband to witness the early display of genius and knowledge in that extraordinary young man.

The next work of our author was properly the physical part of his great system. It appeared at Amsterdam in 1762, under the title of "Considerations on Organized Bodies," in 2 vols. 8vo. Its principal objects were, to give in an abridged form all the most interesting and well-ascertained facts respecting the origin, development, and reproduction of organized bodies; to refute the different systems founded upon epigenesis; and to explain and defend the system of germs. This publication, though well received by philosophers in general, was, from some suspicion of its principles, prohibited in France; but a remonstrance from the author to M. de Malesherbes, then licenser of the press, caused the interdict to be removed, after a new examination. His "Contemplation of Nature," which appeared at Amsterdam in 1764 and 1765, in 2 vols. 8vo, was a work rather meant for popular use, in which the principal facts relative to the different orders of created beings are displayed in a manner both instructive and entertaining, and set off by the charms of an eloquent style; with a continual reference to final causes, and proofs of wisdom and benevolence in the Creator. It has been translated into most of the European languages, and enriched with notes by several hands, as well as by the author himself in a new edition.

The concluding work of Bonnet was his *Paléogénèse Philosophique*, printed at Geneva in 1769 and 1770, in 2 vols. 8vo. In this he treats on the past and future state of living beings, and supports the idea of the survival of all animals, and the perfecting of their faculties in a future state. Attached to this work is "An Inquiry into the Evidences of the Christian Revelation, and the Doctrines of Christianity," which, with a treatise "On the Existence of God," was published separately at Geneva in 1770 and 1771. It was likewise translated into German, and dedicated by the translator to a celebrated Jew, with a challenge to him either to refute it or to acknowledge his conviction of the truth. Bonnet, who had an invincible repugnance for controversy, no sooner heard of this step than he wrote to the Jew, assuring him that he had no share in it; and the two philosophers mutually agreed to forbear any discussion of a topic in regard to which their opinions were totally different, and likely never to coincide. The temper of Bonnet was, indeed, the reverse Bonnet, of that which disposes to contention; and tranquillity was the great object of his life. He readily corrected his own errors; and never but once entered into a defence of himself. This was on occasion of a charge of plagiarism brought against him as having borrowed from Leibnitz his hypothesis on the resurrection. He had, in the earlier part of life, made an anonymous attack, in the Mercure de France, upon Rousseau's discourse on the origin of inequality among men, to which that writer made a reply; but the controversy proceeded no further.

After having in some measure relinquished speculative philosophy, he resumed his attention to natural history, and, in 1773, published, in Rozier's Journal, a memoir on the method of preserving insects and fishes in cabinets. In 1774 he communicated to the same journal a memoir on the loves of plants, originating in the discovery of a kind of cleft or mouth in the pistil of a lily. Some experiments on the reproduction of the heads of snails, and of the limbs and organs of the water salamander, furnished matter for other memoirs. He also made observations on the Surinam toad, on bees, on the blue colour acquired by mushrooms from exposure to the air, and on various other subjects in natural history, which agreeably and usefully occupied his leisure. His reputation was now fully established. There was scarcely an eminent learned society in Europe which did not associate him as a member; and these honours were crowned in 1783 by his election into the small and very select number of foreign associates of the Academy of Sciences at Paris. His literary correspondents were numerous. Amongst these were the distinguished names of Reaumur, Du Hamel, De Geer, Haller, Van Swieten, Spallanzani, and Merian. Although attached by inclination to scientific pursuits in retirement, he did not on that account entirely withdraw from public duties. He entered into the great council of the republic in 1752, and kept his seat in it till 1768; having frequently distinguished himself by the manly eloquence with which he supported wise and moderate measures, and his constant zeal in the cause of morals and religion, on which he thought the prosperity of the state essentially founded. The last twenty-five years of his life he passed entirely in the country, in a simple and uniform mode of life, happy in an easy competence, and in a small circle of friends. It appears that he was for some time engaged in the education of youth, an employment for which he was peculiarly fitted, and in which he secured the warmest attachment on the part of his pupils. The publication of his works, corrected and revised, in a general collection, occupied nearly eight years of his life, which greatly injured his health, from the intense application which he bestowed upon it. This appeared at Neufchâtel in 1797, in 8 vols. 4to, and 18 vols. 8vo; and, besides the works already mentioned, it contains a number of smaller pieces, both in natural history and metaphysics. They are all written in French. It was not till about 1788 that his constitution, feeble as it was, visibly gave way. The symptoms of a dropsy in the chest then began to make their appearance; and these, with some intervals, gradually increased upon him, occasioning a variety of suffering, which he bore with exemplary patience and serenity. He died on the 20th May 1793, at the age of seventy-three. Public honours were rendered to his remains by his fellow-citizens, and his funeral oration was pronounced by his learned friend and kinsman M. de Saussure.

in a general sense, denotes a cover for the head, in common use before the introduction of hats.

in Fortification, a small work consisting of two faces, having only a parapet with two rows of palisades, at about ten or twelve feet distance. It is generally raised before the salient angle of the counterscarp, and has a communication with the covered way, by a trench cut through the glacis, and palisades on each side.

BONNET à Prete, or Priest's Bonnet, in Fortification, is an out-work, having at the head three salient and two reentrant angles. It differs from the double tenaille only in this, that its sides, instead of being parallel, are like the queue d'aronde, or swallow's tail, that is, narrowing or converging at the gorge, and opening at the head.

in sea-language, denotes an addition to a sail.