ON THE NATURAL HISTORY OF INORGANIC BODIES.
The inorganic kingdom presents to the naturalist three divisions of objects of vast importance to our existence and comfort, which correspond with the ancient distri bution of inanimate bodies, under the terms air, water, The natural history of the atmosphere is usually studied in connection with the truths of natural philosophy and chemistry, under the term Meteorology. This is a branch of knowledge which attracted the attention of mankind at a very early period of society. Many curious remarks on the subject occur in the Greek and Roman writers. But it was not until the discovery of the barotneter and thermometer, in the seventeenth century, that any accu rate observation could be made, or general laws deter mined. By means of the former instrument, the weight or pressure of the attnosphere has been determined, to gether with some of the causes which influence its dimi nution and increase, and the signs by which these vari lions are accompanied. The latter instrument has pointed out the changes which take place in the temperature of the atmosphere, according as these depend on the sea sons, the elevation above the level of the sea, and the ac tions of currents. It has enabled us to ascertain the de gree of heat best suited for the growth of animals and vegetables, and those places which are most salutary for valetudinary persons, where the range of temperature is confined. The moisture of the atmosphere can scarcely be said to have been investigated, owing to the imperfection of the instruments employed. Even with regard to the pressure and temperature of the atmosphere, many things yet remain to be determined ; such as the origin of the disturbing causes of the former, and the inflexions in the isothermal lines.
The various appearances which the atmosphere exhi bits at different times, and the changes which these in dicate, have not passed unobserved.
The history of winds is a subject of very great inter est, especially when we attempt to ascertain their pre vailing direction, and the periods of their duration, for the purpose of furnishing the sailor with a knowledge of his dangers, and of regulating the laws of insurance.
The natural history of rain can scarcely he said to have hitherto been studied with care. The appearances of the sky which precede rain were never described with accu racy, until the nomenclature of clouds by Howard ; and since the introduction of definite language, few have stu died the conditions of the phenomena. A careful exa mination of the circumstances under which dew is form ed, enabled Wells to refer its formation to the radiation of heat from the earth's surface. It is more difficult to account for the production of fogs, hail, and snow.
The luminous meteors, including the falling stars, the northern lights and lightning, have arrested the attention of all classes of observers, The naturalist, however, was far from successful in observing the appearances of these phenomena, until the electrician furnished him with an explanation of their origin.
The natural historian, in reference to atmospherical phenomena, is likewise called upon to examine the con dition of those stones, which, at (Efferent peliods, and in different countries, have fallen from the air. Until these conditions arc satisfactorily ascertained, including the ap pearances of the sky previous to their fall, the direction in which they descend, and their temperature when they reach the earth, it will be difficult to determine their origin.
These various changes which take place in the atmo sphere, are accompanied by corresponding changes in other inanimate, as well as animated beings. It is a use ful and pleasing employment to investigate these conco mitant phenomena, and to be able to predict the changes in the weather, from the peculiar appearances presented by plants or animals, and by the atmosphere itself. In this department of the subject, the number of well esta blished facts is, perhaps, greater than is generally sup posed.