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branches; M. folium, with many clefts, and fo on; M. perianthium; M. ftigma; M. cirrhus; M. ftylus. Simplex, with its definition, occurs no fewer than thirteen times; and there are a great many repetitions of the fame nature. This certainly produces one good effect; it adds to the bulk of the book, and confequently to the emolument of the book-maker: but does it add to the information, or diminish the trouble of the iiudent? Botanical terms, even when reduced into the fmalleft compaís, are fo very numerous, as to deter beginners of ordinary fortitude from entering on the ftudy. Whatever, therefore, increases the bulk of the Terminology, muft add to the apparent difficulty of acquiring them, and tend to difguft the ftudent. Had M. Willdenow given the general terms apart from the fpecial ones, he would have prevented much unneceffary repetition. It fometimes happens, indeed, that the fame terms, when applied to diff rent parts, receive a different fignification; and, in fuch cafes, a repetition and feparate explanation becomes neceffary. He has placed the terms which exprefs the arma and pubes under the head fulcra, where few people would think of looking for them; for they are no more props, than they are leaves or branches.
His classification of vegetables, contains a complete account of all the more eminent systems that have been made public, and a good exposition of the Linnæan method, which he prefers to all others. He divides botanical systems into Natural, Artificial and Sexual: we conceive, however, that there are only two, viz. Natural and Artificial. The epithet, Sexual, has been applied to the artificial system of Linnæus, by way of distinction; but this cannot alter its nature. The words Willdenow himself makes use of, in describing an artificial system, are, Some botanists have founded their systems on the number, proportion and agreement, of minute and not very obvious parts; and such a system has been called Artificial.' The Linnæan method, which he wishes to erect into a particular kind of system, is founded on the number, proportion and agreement in different particulars of the parts of generation, which, in most cases, are minute enough: it, therefore, even according to his own definition, can be viewed in no other light than that of an artificial system. His reason for establishing a difference is, that the Linnæan method is partly natural, partly artificial, which is merely an accidental circumstance. There is one mistake he has committed through inadvertence--for it cer tainly could not proceed from ignorance. When mentioning the distinguishing marks by which the orders are determined (p. 149.) he says, The orders of the 15th class are, like the foregoing, taken from the fruit, with this effetence, that here there are no naked seeds, but a sliqua; and the orders are mained, ac
cording to the size of this, Siliculosa and Siliquosæ.' mere size of the siliquæ by no means determines the orders of this class, though, from the names affixed to each, it might naturally be supposed to do so; for there are many plants which Linnæus has placed in his order Siliculose, which have far larger siliquæ than those that are placed in the order Siliquosæ ;-Lunaria, for example. It is the proportion which the length of the germen bears to that of the style, which determines the orders in this class. Those plants, whose germen is short in proportion to the style, are placed in the order Siliculose, and vice versa. Under the head, Botanical Aphorisms, he shows the method of acquiring a knowledge of plants,-gives directions for distinguishing and establishing genera,-points out the different characters by which plants are to be described,-and treats of species and varieties, together with the method of ascertaining them. He has given here a table of 36 colours, which has at least novelty to recommend it; for, as far as we know, nothing of the kind has been attempted by any other writer on natural history. It would have a still stronger recommendation, utility, could pigments of sufficient durability be obtained, and were the colours always mixt up according to the same standard for the different copies, and applied with the same attention. But, unfortunately, most of the pigments we possess, particularly those formed of metallic oxides, are liable to change, when exposed to air and light; and the attention necessary to preserve exact uniformity in the tables prepared for the different copies, could not be expected from any artists that might be employed to paint them. These two circumstances might render a table of this kind a source of error; for in copies printed by different hands, and at different periods, dissimilar tints might stand under the same name. Nevertheless, the design is good, and may be usefully employed to explain what colour is meant to be denoted by the different Latin words employed in natural history. Even when the primary colours are known, an idea of the intermediate shades is imperfectly con- . weyed by words, but they are easily described to the eye. Both methods have been adopted by Willdenow; for in the explanation of his table, he gives a verbal description, which, to make the matter still surer, is frequently illustrated by examples painted by nature.
In his Nomenclature of Vegetables, he has laid down a great many regulations for imposing names on plants. Had something of the same kind been done earlier, botany would not only have rested on a more stable foundation, but botanical language would have been rendered less harsh than it is at present. When the pame of any thing is undetermined and unsettled, the knowledge
of the thing itself is in danger of being lost. The old botanists were not much concerned about preserving the names of plants; for almost every author gave them new ones; on which account, many were disgusted with the barbarous, dry and unfixed nomenclature which prevailed, and declined entering on the study of the most beautiful objects of nature. But, by the introduction of fixed and generally received names, botanists are now able to make themselves understood wherever botany is known. Tournefort first fixed the generic names; but, instead of specific rames, gave only short descriptions. Linnæus, who has contributed more to the advancement of his science than any other man, not only employed generic names, but affixed to each species its trivial name. M. Willdenow objects to long names; to those taken from foreign languages; to those which are already appropriated to animals or fossils; and to those borrowed from religious, moral, anatomical, pathological, geographical, or such subjects: but he wishes the generic name to be taken from the general properties or resemblances of the genus, and to have them formed from the Greek language with a Latin termination, or from the name of some eminent botanist, likewise latinized. Names, however, derived from this last source, are, we think, frequently both harsh and long; such as, Buxbaumia, Gleditschia, Hasselquistia, &c. The specific name is commonly an adjective, expressive of some property of the plant, but should not be taken from properties liable to variation, such as colour. Willdenow objects to substantives as specific names; but we think that no solid objections can be made to Pyrus malus, Prunus cerasus, Brassica rapa, and many others. Some do not approve of the Linnæan method of denoting every plant by a generic and specific name, because genera are only invented by botanists, and have no real existence in nature. Ehrhart, on this account, in his Phytophylaceum, has proposed to distinguish every plant by a single word but what memory could contain the names of all the plants already known, which amount to nearly 80,000 species, formed into about 2,000 genera? Wolf has proposed to denote every character of a plant, by a particular letter, and of these to form the name of the plant. Were this plan to be adopted, such harsh words would be formed, such concurrence of consonants take place, as would render it difficult, if not altogether impossible, for Mr Wolf himself to get his mouth about them.
The Phyfiology of Vegetables, contains a multiplicity of articles, most of which are treated very correctly, and briefly enough; indeed, fometimes a little too much fo. He begins with the different powers of organized bodies, and with the anatomy of vegetables. There is one opinion he advances, to which we can by no
means fubfcribe. He fays, (p. 228.) If we put the feeds of an annual plant into the ground, plants grow from them, which foon flower, produce feed, and then die.' The buds of trees and fhrubs are to be confidered as annual plants; for, as foon as they have bloffomed and fhed their feeds, they decay entirely.' This is certainly not the cafe; for the far greater number of the buds of trees and fhrubs, produce branches which remain for years.
We fhall give what he fays (p. 229.) on the chemical principles of vegetables, as a fpecimen of the method in which he treats his fubject.
The chief vegetable principles are,
1. Caloric, is prefent in all parts of vegetables, and conftitutes their temperature when free.
2. Light, is found in the oils and other inflammable vegetable Tublances.
3. The electric fluid, fhows itself by various electrical phenomena obferved in plants.
4. Carbon, is the chief conftituent part of all vegetables.
5. Hydrogen, this may easily be obtained in a gazeous form, combined with caloric, from all liguminous plants.
5. Oxygen is, we fhall foon find, evolved by the rays of the fun. Part of it, however, is combined with acidifiable bases, and forms vegetable acids.
7. Azote, is exhaled by plants in the night: the greatest part of it, however, is in a combined ftate. Whether azote belongs to the fimple fubftances (elements), or, as Goettling fuppofes, is a compound of oxygen and light, we must leave to the future decifion of chemifts. At prefent, we shall confider it as a fimple fubftance.
8. Phosphorus, occurs in plants of the 15th class, and in the gramina. Its exiftence manifeftly appears, by the fhining of old rotten wood, the root of the common Tormentilla recta, and rotten potatoes, Solanum tuberosum.
9. Sulphur, in form of acid combined with oxygen, is met with in many plants, either with potafs forming a fulphat of potafs, or with foda, as fulphat of foda. Even in fubftance, fulphur has been found in the roots of the Rumex patientia. After they were cut down, boiled, and fcummed, fulphur appeared in the fcum when left to fettle.
11. Soda, is peculiar to almost all plants growing on a fhores or in falt marshes.
12. Silica, is found in the ftem of the Bambufa arundinacea, and in the common reed, Arundo phragmites. It is fuppofed to exift in the alder, Betula alnus, and birch, Betula alba, as their wood often emits fparks when under the hands of the turner.
13. Alumina, it is faid, has been found in fome pants.
14. Magnefia, fome philofophers think, they have met with like
15. Barytes, is chiefly obvious in graffes."
16. Lime, is found in almoft all vegetables, moft frequently in Chara tomentofa, a pound of which is faid to contain five ounces of it.
17. Iron, is detected in the ashes of most plants.
18. Manganefe, has likewise been sometimes found in plants.' There is added in a note,
If fome have detected gold in the vine, Vitis vinifera; oak, Quercus robur; hornbeam, Carpinus betulus; or in ivy, Hedera helix; and tin in Spanish broom, Spartium junceum; it feems merely to have been accidentally, as their prefence has been stated as impoffible by late experiments. Of the above principles, No. 1-7, and 10, 16 and 17, are found in all plants; the reft only in fome. The Fungi, especially the genera Petziza, Octofpera, and Byffus, have, according to the latest refearches, not a veftige of lime.
All the now enumerated principles which have been found in vegetables, belong, as far as chemical knowledge has advanced, to the elementary or fimple fubftances. The vital power produces, by mixing them, new formed fubftances. '
Thefe, however, we must omit for want of room. Among these new productions he mentions Wax. His words are-(p. 231.)
Wax is likewife found in the fruits of fome plants, ex. gr. of the laurel (Laurus nobilis), and of the Myrica cerifera and others. We have it in the pollen of all flowers; and accordingly bees prepare
their wax from it.
The fubftance obtained from the Myrica cerifera is by no means the fame with bees wax; nor do bees form their wax from the pollen of flowers. From a fet of comparative experiments inftituted by Dr Bostock on myrtle wax, i. e. the substance obtained from the Myrica cerifera, bees wax, fpermaceti, adipocire, and the crystalline matter of biliary calculi, it appears that myrtle wax differs from bees wax in fpecific gravity and in its habitudes, with a variety of reagents. The ingenious and decifive experiments of M. Hubert, have proved, in a very fatisfactory manner, that bees form their wax from honey, or any faccharine matter, and that they collect and ftore up the pollen of flowers, only as food for their larvæ.
It would have been fatisfactory to many of his readers, had he mentioned the experiments on which fome of his affertions are founded; or, if this would have occupied too much room, he might have mentioned the authors from whom he had drawn his information. He has abridged the chemical part very much where facts might have been adduced; and extended other parts where nothing but vague hypothefes can be advanced.
After giving the chemical principles of plants, and the fubftan
* Vide Nicholfon's Journal for March 1803.