Class I. PETRÆ or STONES, or, as modern geologists would say, ROCKS.

Steril stones, originating from an earthy principle by cohesion; simple, as being destitute of salt, sulphur, or mercury; fixed, as not being intimately soluble; similar, as consisting of particles united at random.

Order I. HUMOSE. Deposited from vegetable earth, combustible and burning to cinders, their powder harsh and light; as roofing-slate.

Order II. CALCARIÆ. Originating from animal earth; penetrable by fire, and becoming more porous, their powder mealy; and when burnt, they fall into a fine powder; as limestone, marble, gypsum.

Order III. ARGILLACEE. Originating from the viscid sediment of the sea, becoming harder and stiffer in the fire, their powder unctuous before exposure to fire; as serpentine, asbestus, mica.

Order IV. ARENATE. Originating from precipitation caused by rain-water, when struck with steel emitting sparks, very hard, their powder rough and angular like bits of glass; as quartz, jasper, flint.

Order V. AGGREGATE. Originating from a mixture of the foregoing, and therefore participating their constituent particles; their powder differing accordingly; as granite, puddingstone.

Class II. MINERE, MINERALS.

Fertile stones, originating from a saline principle by crystallization; compound, as produced from a stony substance (of the preceding class), impregnated by salt, sulphur, or mercury, intimately soluble in an appropriate menstruum, and crystalline.

Order I. SALIA, Salts. To be distinguished by the taste, soluble in water; as rock-salt, alum, borax.

Dis

Order II. SULPHURA, Sulphureous Minerals. tinguishable by smell, emitting an odour and flaming under the action of fire, soluble in oil; as amber, naphtha, pyrites.

Order III. METALLA, Metallic Minerals. Distinguishable by good eyes! very heavy, fusible, soluble in appropriate acid menstrua; as molybdæna, lead, gold, and copper.

Class III. FOSSILIA, FOSSILS.

Ambiguous stones, originating from modifications of the substances included in the preceding classes.

Order I.

PETRIFICATA, Petrifactions.

with the form of some natural object, as,

Impressed

Zoolithus, the petrifaction of an animal of the class

Mammalia.

Ornitholithus, a petrified bird.

Amphibiolithus, a petrified frog, snake, &c.

Ichthyolithus, a petrified fish.

Entomolithus, a petrified insect or crab.

Helmintholithus, of the class vermes, including shells. Phytolithus, vegetable petrifactions.

Graptolithus, resembling figures produced by painting; as florentine and landscape marble.

Order II. CONCRETA, coagulated from particles agglutinated at random; as urinary and salivary calculi; tartar of wine; pumice, formed by fire; stalactite, formed by air; tophus, produced under water, as oolite.

Order III. TERRE, Earths. Pulverized, their particles loose; as ochre, sand, clay, and chalk.

The first edition of the Systema Naturæ, which consisted of fourteen folio pages, was, as has been already related, printed at Leyden in 1735. That which the author reckoned the twelfth, but which was in reality the fifteenth, is the one that ought to be referred to by naturalists, it being the last that was published under his own care and inspection. It appeared at Stockholm in 1766.

An edition, greatly enlarged, was published at Leipsic by Gmelin in 1788, and contains numerous species not included in any of the preceding. "No

T

nation," says Dr Stoever, " can produce so complete a repertory of natural history as the above. With infinite labour, exertion, and judgment, all the recent discoveries and observations in all the branches of natural science have been united in it." It is, however, as every one who has had occasion to consult it must be aware, a most injudicious compilation, in which a single species is often described under two, three, or even four different names, and in which no improvement corresponding to the advanced state of the science was made in the grouping of the species or genera.

There is an English edition of the same work, translated by William Turton, M. D. 1806, 7 vols 8vo.

London,

"We may venture to predict," says Sir J. E. Smith, in his account of the Life of Linnæus, "that as the Systema Naturæ was the first performance of the kind, it will certainly be the last; the science of natural history is now become so vast, that no man can ever take the lead again as an universal naturalist."

SECTION IX.

Decline and Death of Linnæus.

Review of the Medical Writings of Linnæus-His Materia Medical System of Nosology, Theory of Medicine-His last Work, a Continuation of the Mantissa, published in 1771-Declining State of his Health-In 1774, has an Attack of Apoplexy, followed by Prostration of his Intellectual Powers-Another Attack in 1776, from the Effects of which, and Tertian Fever, he never recovers-His Death in 1778-Honours paid to his Memory.

HITHERTO We have considered Linnæus principally as a naturalist; but his merits in another department of science were such as to entitle him to rank among its more eminent cultivators. It will be recollected, that he practised medicine with success at Stockholm; that he was appointed physician to the Admiralty; that on the resignation of Roberg he obtained the professorship of anatomy, which in the following year he exchanged with Rosen, and became, with the consent of the chancellor of the university, professor of botany. As the latter chair, however, was essentially a medical one, he was bound to direct his attention to the sanative powers of plants, as well as to their uses as articles of food, and was moreover obliged to deliver lectures on materia medica and dietetics. He may even be said to have been the founder of the first-mentioned of these branches of medical science. As a text-book for his lectures, he published an ac

count of the medicinal substances derived from the vegetable kingdom. This treatise, which appeared at Stockholm in 1749, bears the title of Materia Medica, Liber I. de Plantis digestis secundum Genera, Loca, Nomina, Qualitates, Vires, &c. The author seems to have regarded it as one of his most successful performances; for in his private memoirs he remarks of it, that "it is undoubtedly the best work that has appeared in this department of medical science."

In treating of each plant, he first gives its specific character, then a synonyme from Caspar Bauhin, or its discoverer,-thirdly, the country of which it is a native,-fourthly, the Swedish officinal name, the part used, the preparations made of it, and the doses. Its qualities and uses, its effects, the diseases in which it is employed, and the compound medicines of which it forms an ingredient, are then mentioned. At the end of the volume is an index of diseases, with the plants proper for each. Haller's opinion of this work confirms that of Linnæus himself; for, in his Bibliotheca Botanica, he says of it," He has referred to their proper genera very many plants which were highly celebrated for their use in medicine, although their true genus was unknown. He also praises various plants, unknown in the shops, for their healing powers. But it is necessary to read the whole work, which is among the best that its author has produced." Two other parts were published afterwards, one on the animal, the other on the mineral kingdom.

The subject of dietetics also engaged his attention in an eminent degree. In this department, however, he did not write any specific volume, but confined