The mind of man never rests satisfied with the plain truths which it is the business of the natural historian to explore and communicate. It is ever disposed to spe culate and explain, and is frequently better pleased with the representations of the imagination than the gene ralization of the reasoning powers. These remarks are justified by the speculations of geologists. Multitudes who have not examined the actual conditinn of the earth, the existing arrangements of its beds, and the mutual re lations and habitudes of the minerals which compose them, and the systematical characters of petrifactions, and their physical and geographical distribution, neverthcless ven ture to offer explanations of appearances which they have not studied, and assign causes for the production of phenomena, which, had they operated, must have pro duced very different resnits. These pres.umptuous at tempts have been dignified with the name of theories of earth. Hitherto, hotvever, they have borne the same relation to natural history, and geology, properly so call ed, as works of fiction do to genuine history and science. Both serve the same purpose—amusement ;.both are the offspring of the same faculty—the imagination.
It would serve many useful purposes were the term 0 o 2 geognosy limited to express our knowledge of the actual condition of the earth, without a reference to theory, or to include nothing mote than the natural history of mi nerals. Geogriosy would in that case be occupied in preparing the mind for the application of the discove ries of science to the explanation of the phenomena, and -would constitute the safe road to Geology. This last mentioned department of human knowledge has advanc ed with a slo‘v ancl unsteady pace. Attempting to arrive ;at its desirable objects without traversing the fields of geognosy, its votaries have bewildered themselves, and have drawn down no inconsiderable share of popular de rision. Eagerly attempting to account far the inclined position and other h.regularities of the older rocks, they have refused to investigate similar phenomena which present themselves in every sand hill. They have ex erted themselves, without success, to explain the appear ances of a coal-field, because they have overlooked si milar appearances more recent and intelligible, exhibited by every peat-moss seated in a valley. 'The geologist, however, has made at least one important step in the in quiry, by having determined the density of the earth. It is lightest at the surface, and this arrangement appears to have been produced by the same cause which gives to the atmosphere its increased rarity as we ascend. Geo
logists have been less fortunate in their attempts to de termine the figure of the earth. Anxious to establish its form as a spheroid of equilibrium, they have tried in vain to reconcile the opposing. results of trigonometrical mea surements, and have shut their eyes against the indica tions of its irregularity, exhibited by the elevation of the mountains, and which might have been inferred from the extensive revolutions which it has undergone. The earth is not yet old enough to be regular in its form.
Having thus marked the peculiar objects of the natu ralist in reference to inorganic bodies, and having deli neated the leading features of the sciences of meteorolo gy, hydrography, and mineralogy, we come now to con sider natural history as occupied with living bodies.
oN THE NATURAL HISTORY OF ORGANIZED BODIES.
This department of knowledge is termed botany. Those who have cultivated this pleasing study have pur sued very different methods of investigation, and have arrived at very different results. One class of observ ers have devoted their labours to the naming of plants, and to the discovery of those marks by which they may be recognised in their arbitrary arrangements. The followers of this humble occupation attempt to establish what is termed the artificial nzethod. Another class of observers, with more enlightened views, attend to all the characters of every organ, and leave no form or change unexploted. They examine the seed, and its mode of germination ; the root, and the qualities by which it is fitted to act as an organ of nutrition and support; the stem, its peculiar structure, and the origin and position of its branches'; the leaves, their peculiar forms, posi tion, and duration ; the flowers, the structure of their protecting calyx, and delicate corolla ; the fruit, the period of its ripening, and the mode in which the seeds are disseminated. Botanists who attend to all these char acters, and found their systematical arrangements in refe rence to the whole, attempt to introduce what has been termed the natural method. The followers of this me thod prepare the way for the physiologist, who attempts to explain the uses of the different organs, and by expe riment to establish the truth of his opinions.
The botanist does not occupy himself exclusively with study ing the forms of the various organs of plants. Hc examines their condition in reference to their physical and geographical distribution, for the purpose of dis covering the circumstances which regulate the transla tion and naturalization of plants.