he employed for this purpose, were, the duration and size of plants; presence, or absence of flowers; the number of cotyledons; the situation of the seed, as erect or pendent; the adherence of the pericarp to the seeds; the number of cells in the pericarp, and the number of seeds which they contained; the adherence of the calyx to the germ; and the nature of the root, whether bulbous, or fibrous. This method was too imperfect to be followed, having neither the simplicity nor the unity to render its application useful.

John Bauhin, though younger than Gesner, was his friend and pupil; he composed a general history of plants; this was a work evincing great learning and accurate investigations. Gaspard Bauhin, the younger brother, no less active and learned, conceived the design of a work which should contain a history of all known plants, together with the different names which other writers had applied to the same plant. Clusius and the elder Bauhin had imagined something like a genus of plants, formed by the grouping of similar species, but Gaspard Bauhin expressed this more decidedly in remarks upon generic distinctions. His work, the result of forty years' labour, was of great assistance to Linnæus, in perfecting our present system of Botany.

We find, in looking back upon the labours of botanists during the 16th century, that more had been accomplished than during any former period; the character of novelty and originality exhibited in these researches, is highly creditable to those who thus led the way in the march of improvement.

The 17th century, in its commencement, was not favourable to the sciences. Europe was agitated by continual wars, and the arts of peace were neglected; but in the last part of that age, a taste for natural history revived; men of highly gifted minds applied themselves to the study of Botany, and many undertook long voyages, with the sole design of examining foreign plants. Botanists were astonished at the great number of interesting plants discovered by travellers, in the region of South Africa, around the Cape of Good Hope, and in the East India Islands.

Two Dutch botanists of the name of Commelin, who wrote about this period, are commemorated in the beautiful genus Commelina, first discovered in America. Bonnet* of Geneva, a close observer of facts, wrote upon the "Nature and Offices of Leaves ;" and a work entitled, "Contemplation of Nature, or the Regeneration of Beings." Two writers of the name of Camararius are distinguished in the annals of the science for learning and ingenuity. Gaertner of Germany wrote upon fruits, or, as he termed this department of the science, Carpology. He dissected, the fruits of more than a thousand plants, the figures of which he designed and engraved. To Gleditsch, professor of Botany at Frankfort, is dedicated the genus Gleditscha. Rudbeck the younger, who preceded Linnæus as professor of Botany in Upsal, was, by the latter, commemorated in the genus Rudbeckia.

At this period, the plants of our own country began to excite the curiosity of scientific Europeans. Louis XIV. sent to America, Plumier, a man celebrated for his mathematical and botanical knowledge, and who was styled, botanist to the King. He made three voyages, and gave drawings and descriptions of more American species than any other traveller had done.

*Pronounced Bonnay.

Characters employed by him in the formation of classes-The Bauhins-Retrospect of the 16th century-Botany in the 17th century.

About this time, the practice of naming newly-discovered plants after distinguished botanists became common. History now presents us with many who were distinguished by their efforts in the cause of science, but a notice of each individual would carry us beyond our limits.

Botanists now began to study the stamens and pistils of plants ; and it was suggested that the science would remain imperfect as long as species and genera were undefined. Orders and classes also were recommended, and natural resemblances and affinities studied, A work was written upon the umbelliferous plants ;* this was the first attempt at describing in one mass any single group of plants by characters peculiar to the whole. This was followed by several attempts to form a natural method of classification; among the most approved of these methods was that of Ray, who published a work called "A General History of Plants;" in this he divided all Plants into 33 classes, 27 of which were composed of herbs, the rest of trees.

The first botanist who thought of classing plants without any reference to their being either herbs or trees, was a German, of the name of Rivannus, who proposed to consider, as the foundation of classification, the absence or presence of flowers; the manner in which they were situated, or their inflorescence; the number of petals; the regular or irregular form of the corolla; the adherence or non-adherence of the calyx to the germ; the nature of the pericarp; the number of seeds, and of cotyledons.

A botanist of the name of Magnol, at this time, was honoured by having his name given to the splendid Magnolia, an American plant, which then began to be known in Europe.

Joseph Pitton de Tournefort was born in 1656. While very young, he discovered an enthusiastic fondness for botanical pursuits: he had been destined by his friends for a profession; but his genius seemed so strongly bent upon the study of nature, that he was at length permitted to indulge without restraint in his favourite pursuits. He ranged over the Alps and Pyrenees, and many provinces of France, collecting the flowery treasures offered by those fertile regions; often in peril from banditti, and exposing his life to hazards in climbing terrific precipices, or amidst the glaciers of the mountains.

The method of Tournefort, which was founded upon the form of the corolla, although imperfect, greatly assisted the progress of that botanist who stands unrivalled in this department of Natural History. You do not need to be told that we here refer to Linnæus.

You will observe that the attempts of botanists, until this time, had been chiefly directed towards the attainment of some proper method for the arrangement of plants; the attention of some investigating minds was now turned towards their Anatomy and Physiol ogy. Since the days of the first Greek naturalists, these departments of botanical science had lain neglected; but the confused opinions of the ancients now served to suggest experiments, which resulted in new observations and solid discoveries.

The invention of the microscope threw light upon the mysteries of

*The author of this was Robert Morrison, a Scotchman. These monographs, or descriptions of single families, are now of great value; no botanist can thoroughly investigate the whole vegetable kingdom; but by close attention to one department, important discoveries may be made.

Botany-Ray-Rivinius-Magnol-Tournefort-Attention of botanists turned towards anatomy and physiology-Microscope.

Various improvements in

nature, which, without this instrument, must ever have remained in obscurity; by its assistance botanists studied the internal structure of vegetables; they described the heart, wood, and pith; they perceived the newly formed bud, yet invisible to the naked eye; the future plant existing in the bulbous roots, and even in the seed; pores were discovered, which were found to be the organs of the expiration and inspiration of gases, thrown out as noxious, or inhaled as nutritious.* The importance of the stamen and pistils as essential to the perfection of the seed of vegetables began to be suspected.

As yet, however, the science of Botany lay in scattered fragments of various imperfect and contending systems; much labour had been bestowed, and great improvements made, but there was no central point around which these improvements might be collected. The learned world were sensible of the deficiency; but it required genius, great observation of nature, and courage to stem the tide of popular prejudices, in him who should come forward to attempt the work of reform.

Charles Von Linnæus, an inhabitant of Sweden, suddenly emerging from obscurity, offered to the world a system of Botany, so far superior to all others, as to leave no room for dispute as to its comparative merit. All preceding systems were immediately laid aside, and the classification of Linnæus was received with scarcely a dissenting voice. What this system was, you have not now to learn, since it was the alphabet of your botanical studies. Linnæus extended the principles of his classification to the animal and minerał kingdom; in the language of an eminent botanist, "His magic pen turned the wilds of Lapland into fairy fields, and the animals of Sweden came to be classed by him as they went to Adam in the garden of Eden to receive each his particular name."

LECTURE XLV.

HISTORY OF BOTANY FROM THE TIME OF LINNEUS TO THE PRESENT.

LINNÆUS was born in 1707; his father was a clergyman, and had designed his son for the same sacred office; but seeing him leave his studies to gather flowers, he inferred that he possessed a weak and trifling mind, unfit for close investigation; he was about to put him to a mechanical employment, when some discerning persons perceiving in his devotion to the works of nature the germ of a great and lofty mind, placed him in a situation favourable to the development of his peculiar talents, where he was allowed, without restraint, to study the book of nature,

"This elder Scripture, writ by God's own hand."

Linnæus formed anew the language of botanical science; every organ of the plant he defined with precision, and gave it an appropriate name; every important modification was designated by a particular term. Thus comparisons became easy, and confusion was avoided. The characters of plants appeared in a new light. Each species took, besides the name of the genus to which it belonged, a specific name which recalled some peculiarity distinctive of the Leuwenhoek, Grew, Malpighi, and Camerarius, are among the first of the moderns who investigated the internal structure of vegetables.

† Sir James E. Smith.

Science of botany yet imperfect-Linnæus-Birth of Linnæus, &c.-What were the improvements made by Linnæus ?

species. Before that time the species, instead of being thus designated, required in some cases a whole sentence to express the name. But what most tended to render the works of Linnæus popular, was his artificial system, in which he had made the stamens and pistils subservient to a most simple and clear arrangement; he remarked the different insertion of the stamens; their union by means of their filaments had been before observed, but he employed them in a manner entirely original.

This "Northern Light," as he has sometimes been termed, contributed to the progress of physiology both by his own discoveries, and by improving upon the suggestions of those who had gone before him. In the details of science, he was no less accurate than bold and comprehensive in his general views. The world knew not which to admire the most, the multiplicity, the novelty, or the profound views of this modern Aristotle. His school became the resort of men of science from all Europe; and he seemed to have acquired that influence over the human mind, which had been peculiar to the ancient philosophers of Greece. The defects of this great man, for human nature is never without its imperfections, were, that he sometimes carried too far a favourite idea; endowed with a brilliant imagination, he was at times somewhat blinded by the beauty of his conceptions, and strove to reconcile nature to the visions of his own fancy.

We have, in our investigations of the artificial system, occasionally pointed out some imperfections, particularly in the separation of natural families; but no means of remedying these have yet been found, and after the lapse of near a century, with the exception of a few alterations, we still receive this system as left by its author.

Linnæus died in 1778; he is honoured among the scientific by a title far more proud that any hereditary distinctions, that of" Prince of Naturalists." The most important works of this great man are, "Philosophy of Botany," "Genera and Species of Plants," "System of Nature," and "Flowers of Sweden, Lapland," &c. The Linnæa borealis was dedicated to him by Gronovius. Ten years after his death, a society, distinguished by his name, was founded in London; this is now in possession of his library, herbariums, collections of insects and shells, with numerous manuscripts. Sir James Edward Smith was the founder of this society, and its first, and only president until his death, which has recently occurred. He translated the writings of Linnæus, and illustrated them by his own comments.

The study of plants, after the discoveries and classifications of Linnæus, became, in a degree, general. The knowledge of vegetable physiology began to be usefully applied to agriculture. Duhamel, of France, very successfully laboured to exhibit the connexion between the science of Botany and the cultivation of plants. Bossuet, of Geneva, proved by experiments that the vascular system of plants is tubular and transparent; and that leaves perform the office of respi

ration.

Grew, of England, had, before this period, ascertained the existence of the cambium, and Duhamel afterward proved that it was distinct from the sap and proper juices. The latter opposed the idea, till then entertained, that earth and water were the only food of plants; he proved that the various solids and fluids diffused in the soil and atmosphere, are all important to vegetation.

What most rendered his works popular?-How did he contribute to the progress of physiology, &c. ?-Death of Linnaeus-Linnean Society in London-Botany after the death of Linnæus-Duhamel and Grew.

The observations of Priestley, Saussure, and others, aided by the discoveries made in pneumatic chemistry, of the existence of oxygen, hydrogen, and carbonic acid gases, formed a new era in the history of vegetable physiology. It was proved that vegetables do ultimately consist of oxygen, hydrogen, and carbon, sometimes of a small quantity of nitrogen, combined with mineral salts, and often some silex, sulphur, and iron. These elementary substances were found to be diffused through air and water, and the animal and vegetable substances which the latter holds in solution: the green parts of vegetables were observed to exhale oxygen in the light, and carbonic acid gas in the dark; and the carbon left by the decomposition of the carbonic acid, was shown to be incorporated into the vegetable substance, giving to the wood its strength and hardness.

He

The naturalist whose labours, in point of utility, will best bear a comparison with those of Linnæus, is Bernard de Jussieu. was remarkable for the extent of his knowledge, the penetration of his genius, and the solidity of his judgment. He is said to have been unambitious. The love of truth and science were with him sufficient excitements to the most severe labour. "Many of our contemporaries," says Mirbel, "knew this sage; they say that never have they seen so much knowledge combined with so high a degree of candour and modesty." To this botanist we are indebted for a natural method of classification, superior to those of his predecessors.

Jussieu proposed a method of classing plants according to certain distinctions in the seed, which were found to be universal; this was perfected and published by his nephew, Antoine-Laurent de Jussieu, and is now generally received as the best mode of natural classification which has yet been discovered. This method is called natural, because it aims to bring into groups such genera of plants as resemble each other in medicinal and other properties; while the system of Linnæus is called artificial, because, by a certain rule, plants which have no such resemblance in their properties are brought together. We therefore find in one of the Linnæan classes the poisonous flag and the nutritious grass, the grain which supports life and the darnel which destroys it; in another, the healthful potato and the poison mandrake, the deadly hemlock and the grateful coriander. Throughout this system we meet with similar contrasts in the qualities of the plants which are collected into the same classes. Nor are their external appearances less unlike; for here the oleander and pigweed, the tulip and the dock, meet in the same classes. This system, it should always be remembered, is not the whole science of Botany, but is the key to the natural method, by which alone, we should find great difficulty in ascertaining the names of plants; it is, as it were, a stepping-stone by which we must ascend to the valuable knowledge which cannot well be reached in any other way. The more practical a botanist becomes, the less need he has for this assistance; the eye becomes quick to seize on natural characters without reference to the dictionary, as the artificial system is aptly termed. Thus a pupil, in studying a language, may, in time, be able to dispense with his dictionary; though he could not have proceeded, at first, without its assistance. For more particular explanations of Jussieu's method, you are referred to the comparison of that with the method of Linnæus and Tournefort in the remarks on classification, and to the Natural Orders contained in the appendix.

Priestley, &c.-Character of Jussieu-Natural method of classing plants.