Графични страници
PDF файл

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 depart. ment 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 Physiology. 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 observa. tions and solid discoveries.

The invention of the microscope threw light upon the myste. ries of 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

gasses, thrown out as noxious, or inhaled as nutritious. The importance of the stamens 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 seemed to be no central point around which these improvements might be collected; the learned world were sensible of the deficiency; but it required genius, great observa. tion of nature, and courage to stem the tide of popular preju. dices, in him who should come forward to attempt the work of reform.

Charles 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

See part III.

+ Leuwenhoek, Grew, Malpigh, and Camerarius, are among the first of the moderns who investigated the internal structure of vegetables.

Attention of botanists turned towards anatomy and physiology Microscope --Seience of botany yet imperfect--Linnæus,

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 has been the basis of your botanical studies. Linnæus extended the principles of his classification to the animal and mineral kingdoms ; 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.”


History of Botany from the time of Linnæus to the present.

LINNEUS 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 in. vestigation; and was about to put him to a mechanical em. ployment, 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 de.. velopement 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 de. signated 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 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

* Sir James E. Smith.

Birth of Linnæus, &c.-What were the improvements made by Linnæus ?What most rendered his works popular ?

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 influ. ence 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 own con. ceptions, and strove to reconcile nature to the visions of his own fancy.

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

Linnæus died in 1778; he is honoured among the scientific, by a title far more proud than any hereditary distinctions; he is termed « Prince of Naturalists.Ten years after his death, a society distinguished by his name, was founded in London ; this society is now in possession of his library, herbariums, col. lections 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 oë. curred. He translated the writings of Linnæus, (which were originally in Latin,) and illustrated them by his own comments : no one, perhaps, has done more towards rendering botanical science accessible to all classes of people than this elegant writer.

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

How did he contribute to the progress of physiology, &c.?-His defectsDeath of Linnæus--Linnæan society in London-Botany after the death of Linnæus.

cultivation of plants. Bossuet of Geneva proved by experi. ments that the vascular system of plants is tubular and tran. sparent; and that leaves perform the office of respiration.

Grew of England ascertained the existence of the cambium, and Duhamel afterwards 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.

The observations of Priestly, 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, and sometimes of a small quantity of nitrogen, com. bined with mineral salts, and often some silex, sulphur, and iron, which seem important to vegetable life. These elementary substances were found to be diffused through air and wa. ter, 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 ofthe carbonic acid, was shown to be incorporated into the vegetable substance, giving to the wood its strength and hardness.

The only naturalist who can bear any comparison with Lin. næus, is Bernard de Jussieu. He was remarkable for the ex. tent 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 excite. ments 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 the natural method of classification, with which you have been made acquainted.*

Jussieu proposed a method of classing plants according to certain distinctions in the seed, which were found to be universal ; this method was perfected and published by his nephew, Antoine-Laurent de Jussieu, and is now universally received as the best mode of natural classification which has yet been discovered. We call this method natural, because it aims to groups

of plants as resemble each other in medicinal and other properties, while the system of Linnæus

bring into

such genera

* Soe Parts I. and III.

Grew and Duhamel-Priestly, &c.-Character of Jassieu.

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 potatoe and the poison mandrake, the deadly hemlock and the grateful coriander. We might thus go through this system and constantly meet with similar contrasts in the qualities of the plants which are here 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 in a de. gree to dispense with his dictionary ; but he could never have proceeded thus far without its assistance. For more particular explanations of Jussieu's method, you are referred to the com. parison of that with the method of Linnæus and Tournefort in the remarks on classification.

Adanson, previous to the time of the younger Jussieu, had published a system of classification, in which he arranged plants according to the resemblance observed in all their or. gans. In one class, all which had similar roots were placed; in another, all which had similar stems; a third was arranged by resemblance of leaves, in their forms and situations; but the most important distinctions he considered as founded upon organs of fructification.

Among other botanists we would notice L. C. Richard, who wrote in French an interesting account of the Orchideæ of Europe, and assisted in compiling from ancient works a very useful botanical dictionary.

Des Fontaines first showed that the stems of monocotyledonous and of dicotyledonous plants differ from each other in their structure, and modes of growth ; he divided them into endogenous, growing inwardly, as the palms ; and exogenous, growing outwardly, as the oak.

France is distinguished for the number and accuracy of its naturalists. Mirbel, a distinguished professor of botany in


French Naturalists.

« ПредишнаНапред »