either thrive or languish according to the wholesome or hurtful application of these stimulants. The spontaneous movements of plants are almost as readily to be observed as their living principle. The general direction of their branches, and especially of the upper surface of their leaves, though repeatedly disturbed, to the light, the unfolding and closing of their flowers at stated times, or according to favourable or unfavourable circumstances, with some still more curious particulars, are actions undoubtedly depending on their vital principle, and are performed with the greater facility in proportion as that principle is in its greatest vigour. Plants alone have a power of deriving nourishment, though not indeed exclusively, from inorganic matter, mere earths, salts, or airs, substances certainly incapable of serving as food for any animals, the latter only feeding on what is or has been organized matter, either of a vegetable or animal nature. So that it would seem to be the office of vegetable life alone to transform dead matter into organized living bodies. The Mineral kingdom can never be confounded with the other two. Fossils are masses of mere dead unorganized matter, subject to the laws of chemistry alone; growing indeed, or increasing by the mechanical addition of extraneous substances, or by the laws of chemical attraction, but not fed by nourishment taken into an organized structure. Their curious crystallization bears some resemblance to organization, but performs none of its offices, nor is any thing like a vital principle to be found in this department of nature. If it be asked what is this vital principle, so essential to animals and vegetables, but of which fossils are destitute, we must own our complete ignorance. We know it, as we know its omnipotent Author, by its effects. The infinitely small vessels of an almost invisible insect, the fine and pellucid tubes of a plant, all hold their destined fluids, conveying or changing them according to fixed laws, but never permitting them to run into confusion, so long as the vital principle animates their various forms. But no sooner does death happen, than, without any alteration of structure, any apparent change in their material configuration, all is reversed. The eye loses its form and brightness; its mem branes let go their contents, which mix in confusion, and thenceforth yield to the laws of chemistry alone. Just so it happens, sooner or later, to the other parts of the animal as well as vegetable frame. Chemical changes immediately follow the total privation of life, the importance of which becomes instantly evident when it is no more. If the human understanding can in any case flatter itself with obtaining, in the natural world, a glimpse of the immediate agency of the Deity, it is in the contemplation of this vital principle, which seems independent of material organization, and an impulse of his own divine energy. The man who surveys the vast field of nature, and devotes a portion of his time to the study of the principles which influence, or govern, the motions of animated beings, however minute they may be, will not only derive pleasure from the pursuit, but he will gain the only means of discovering the object and utility of their creation. And as he journeys along from one gradation of knowledge to another, he will become more and more intimate with the designs of the great Creator of all. He will gain a more comprehensive view of that wonderful and illimitable power which hath organized the universe, for purposes with which, in the fulness of time, the wise and the virtuous will doubtless be made acquainted. But knowledge must ever be progressive; and he who makes the attempt to read the characters by which the wisdom, power, beneficence, and eternal nature of God is stamped upon every thing here below, will not do it in vain. He suits to nature's reign th' inquiring eye, From Matter's mode through Instinct's narrow sway, To Reason's gradual but unbounded way, And sees through all the wonder-varied chain No link omitted, no appendage vain, But all supporting and supported, till The whole is perfect as the AUTHOR'S will. Hence even the meanest points of Nature's care The pebble, through pellucid waters shown, The moss that clothes-the shrub that cleaves to stone, The herds that graze, the flocks that nip the plain, These hold ten thousand wonders to the sight, properties-proportions-ends- Until unnumbered sparks around him fall From the Great Source of Light, and Life, and All! QUESTIONS-1. How are the productions of nature divided? 2. What is said of the organization of animals? 3. Of vegetables? 4. What are fossils or minerals? 5. What do we know of the vital principle? LESSON 76. Mineralogy. An'alyze, to resolve a compound into its constituent parts, for the purpose of examination. Physical, natural, relating to na ture. ALL the solid materials of which this globe of ours is composed have received the name of Minerals; and the science which makes us acquainted with the relations under which they present themselves to us, is distinguished by the title Mineralogy. These substances, without doubt, must have at all times attracted the attention of mankind; because from them alone are drawn the metals, stones, and other similar substances of indispensable use. But it is only very lately that the method of ascertaining the component parts of these substances was discovered, or that it was possible to describe them so as to be intelligible to others, From the ancients no information of any consequence on these topics is to be expected. The whole science of mineralogy has been created since the year 1770, and is at present advancing towards perfection with astonishing rapidity. New minerals are every day described and analyzed, collections are every where forming, and travels of discovery are succeeding each other without intermission. The fruit of these labours has been the discovery of several new earthe and metals; besides a vast number of useful minerals which had been formerly unknown or disregarded. Nothing at first sight appears easier than to describe a mineral, and yet in reality it is attended with a great deal of difficulty. It is obvious, that to distinguish a mineral from every other, we must either mention some peculiar property, or a collection of properties, which exist together in no other mineral. These properties must be described in terms rigidly accurate, which convey precise ideas of the very properties intended, and of no other properties. The smallest deviation from this would lead to confusion and uncertainty. Now it is impossible to describe minerals in this manner, unless there be a peculiar term for each of their properties, and unless this term be completely understood. Mineralogy, therefore, must have a language of its own; that is to say, it must have a term to denote every mineralogical property, and each of these terms must be accurately defined. The language of mineralogy was invented by the celebrated Werner, of Freyburg, and first made known to the world by the publication of his treatise on the External Characters of Minerals. The object of this philosopher was to invent a method of describing minerals with such precision, that every species could readily be recognised by those who were acquainted with the terms employed. For this purpose, it was necessary to make use of those properties only which presented themselves to our senses on inspecting the mineral. These accordingly were chosen, and called by Werner external characters; because they may be ascertained without destroying the mineral examined. These constitute the first division of the characters of minerals. To the second belong those which are derived from the chemical composition, or discovered by any chemical change which the mineral suffers; to the third are referred those properties which are afforded by certain physical characters, as electricity or magnetism; and to the fourth a few characters, derived from circumstances frequently observed with regard to a mineral, as the place where it is found, or the minerals by which it is usually accompanied. QUESTIONS.-1. What are minerals? 2. What is mineralogy? 3. What is said of the knowledge which the ancients had of minerals? 4. What has been the state of this science since the year 1770? 5. How must minerals be described? 6. What was the object of Werner 174 CLASSIFICATION OF MINERALS. in inventing the language of mineralogy? 7. What was necessary for this purpose? 8. Why were they called external characters? 9. What are the three other divisions of the characters of minerals? 10. What are the general external characters of minerals? (See Appendix.) 11. Particular external characters? 12. What farther descriptions are given? LESSON 7. Classification of Minerals. Lap'idary, one who deals in gems, or precious stones. MINERALS are usually arranged under four classes; earthy, saline, inflammable, and metallic. The earthy minerals contain all such as derive their qualities from the earths; and they are divided into genera, according to the particular earth which predominates in each, or more properly, into families, according to their resemblance in external characters, as the diamond family, the ruby family, talc family, and others. The diamond, of which there is only a single species, is the hardest and most beautiful of all the mineral productions. When heated to the temperature of melting copper, and exposed to a current of air, it is gradually but completely combustible. It is wholly converted into carbonic acid, and therefore consists of pure carbon, as we have already mentioned. By means of diamond powder, this substance can be cut and polished upon a wheel in the same way as any other gems are wrought by emery. It is manufactured by jewellers into brilliants and rose diamonds; and is employed by glaziers for cutting glass; by lapidaries for cutting and engraving on the hardest gems, and in the finer kinds of clock work. Before the discovery of the Brazilian mines, diamonds were much more rare, and of course dearer than they have been since. In the year 1730, eleven hundred and forty-six ounces were brought to Europe; in consequence of which, the price of this article immedi ately fell three-fourths, and to prevent a still further depreciation, the Portuguese government restricted the number |