CHARLES, an eminent naturalist, was born in 1720 at Geneva, 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 deafness, with which he was very early afflicted, he put him under the care of a domestic tutor, and under him his progress was rapid and successful in general literature. At the early age of 16, his attention was so deeply engaged in the perusal and study of Le Spectacle de la Nature, that it seems to have directed the bias and taste of 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 in natural history. He discovered the haunts of this curious insect, watched and studied its manners and habits, and added many observations to those of Poupart 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.

Young Bonnet had been destined by his father to 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 correspondent 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 as he never afterwards recovered. 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 polype. 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 stigmata has been given. It was about the same time that he made some curious discoveries respecting the tinea, or tapeworm. In the year 1743, when he was raised to the rank of doctor of laws, he procured a welcome dispensation Bonnet. dispensation from the farther 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 communicated 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. The want of delicacy was objected to in some journals, which, it was alleged, appeared in his descriptions of the mode of propagation of tree-lice.

But the constant labours to which Bonnet had subjected himself in all his inquiries began to produce very serious consequences on 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. Like a true philosopher he bore his afflictions with patience. But he was not idle: for though he was interdicted from all observation, his mind was fully occupied in reflection. After some time's relaxation from his usual pursuits he was at last restored to tolerable health and ease, 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, his "Inquiries into the use of the Leaves of Plants." This work was first published in 4to at Leyden in 1754. A supplement was added to it in 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 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 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 abridgement of the materials he had collected, under the title of an "Essay on Physiology," published in London in 1755, but without his name, nor did he acknowledge it till near 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 predestination, 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 usually established methods. It was the freedom with which he had discussed some of these delicate points, and the fear of being involved in personal controversy, which induced the author to remain so long concealed. It met with a number of critics, yet its success was brilliant.

The next work of Bonnet was a development of part of the substance of the preceding, viz. 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." This was first printed at Copenhagen in 1760, in 4to, at the expense of the king of Denmark. In this work, like that of the abbé Condillac, he takes the supposition of a statue organized like the human body, which he by degrees animates, and shows how its ideas would arise from impressions on the organs of sense. This work was well received by philosophers, though with some it subjected him to the 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 was devoted. His retired and studious habits, together with his deafness and other bodily infirmities, had ever prevented him from joining in the assemblies of the young and gay; at the same time they rendered domestic comforts more essential to him. In 1756, he married a lady of the respectable family of de la Rive, and with her he passed thirty-seven years of that perfect union which results from mutual tenderness, directed by good sense and virtue. The celebrated Sauflure was the nephew of Mad. Bonnet, and it was no small pleasure to her husband to witness the early display of genius and knowledge in this 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," 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. des Maleherbes, then licensor of the press, caused the interdict to be removed, after a new examination. His "Contemplation of Nature;" which appeared in 1764, Amst. 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 the 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. Bonnet. The concluding work of Bonnet was his "Palingenesie Philosophique," printed at Geneva in 1769, 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. It was likewise translated into German, and dedicated by the translator to a celebrated Jew, with a summons to him to refute it, or acknowledge his conviction. 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 which their opinions were totally different. The temper of Bonnet was, indeed, the direct reverse 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 French Mercury upon Rousseau's discourse on the origin of inequality among men, to which that writer made a reply; but the controversy went 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 fish 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 pipa or 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. Among these were the distinguished names of Reaumur, Du Hamel, De Geer, Haller, Van Swieten, Spallanzani, and Merian. Though attached by inclination to the pursuit of scientific studies in retirement, he did not entirely withdraw from public duties. He entered into the great council of the republic in 1752, and kept his seat in 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 living, 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 obtained the warmest attachment of his pupils. The publication of all his works, corrected and revised, in a general collection, occupied near eight years of his life, which greatly injured his health, from the intense application which he bestowed upon it. This appeared at Neufchatel, in 9 vols 4to, and 18 vols 8vo.; and besides the works already mentioned, 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 dropy in the chest then began to manifest appearance; and these with some intervals, gradually increased upon him, occasioning a variety of sufferings, which he bore with great patience and serenity. He died on May 20. 1793, at the age of 73. Public honours were rendered to his remains by his fellow-citizens, and his funeral eulogy 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. Bonnets are still used in many parts of Scotland.

in Fortification, a small work consisting of two faces, having only a parapet with two rows of palisadoes, at about 10 or 12 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 palisadoes on each side.

BONNET à Pretre, or Prièr Bonnet, in Fortification, is an out-work, having at the head three salient angles, and two inwards. 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 drawing close at the gorge, and opening at the head.

in the sea-language, denotes an addition to a sail; thus we say, lace on the bonnet, or shake off the bonnet.