derable, of a similar or other body suspended on the opposite: as in each case the intrinsic specific gravity of the body itself is still the same, and is only altered by reason of a similar action being opposed to, at the time, and coming into collision with it. And (as is the case of the summits or higher regions of mountains,) any circumstance which varies or disturbs the equilibrium of the action of gravitation on the atmosphere, has the effect of disposing it, more or less, to the species of meteoric action in which rain has its source, and vice versa. Thus if, for instance, a comet happened to approach so near to the earth, as that, similar to the larger class of meteors, the local concentric action of the electric and magnetic forces on it, had the effect of disturbing the equilibrium of its gravitation in the atmosphere. It is easy to see that, on the principle noticed, the seasons of the approach of such bodies would be more or less remarkable for rain; and, on the contrary, that when comets ranged at such a distance as that, without affecting the local action of gravity on the atmosphere, by increasing the sum of reflective action, they rather added thereto; the contrary, or increased drought in the seasons would be the result.

CHAP. IX.

Application of Principles:-Climate, in Reference to the Geographical Distribution of Animals and Plants.

Be this however, as it may, as in treating of the assumed connexion of planetary influence with the changes of the seasons, we shall have to resume, on different grounds, the subject of comets: having thus touched in detail on the leading phenomena connected with the earth and its atmosphere; and guided at once by observation and experiment, traced them, as assumed, to their respective causes, or first principles: we shall now proceed with the no less important task of showing the application which may be made of these principles to some of the various objects of utility with which they are connected.

These objects may be classed under the following general heads, viz. as connected with climate, in reference to the geographical distribution of animals and plants; with minearology; with earthquakes, and volcanic action; with localities, in reference to their assumed influence on the temperature and weather; with planetary and cometary influence on the seasons; and finally, as connected with the equi

noctial phenomena, and the lunar action on the weather.

And first as regards climate:-were the principle of temperature in the atmosphere, derived from the opposite actions, electrical and magnetic, of the sun; the whole of the dispositions and mechanism of nature in the earth and remainder of the planets, whether local or external, as connected with the temperature, the variations in the animal and vegetable kingdoms connected with those of climate, or the phenomena of the seasons and weather, would be found in accordance therewith; so that, deprived of all other, the facts connected with the latter would, of themselves, serve as the most certain and conclusive proofs, in reference to the correctness of the principles assumed.

In proof of this, as connected with that most important subject, the geographical distribution of animals and plants:-owing to the circumstance that the magnetic, equally as the electric action of the sun, is one of the principles which enters into and determines the peculiar nature of climate as connected with the constitution of animals and plants; and that the positions of the opposite main foci of the magnetic action of the sun in either hemisphere, or magnetic poles, are equally fixed and invariable, as the position occupied by that of its electric action at the Line. This causes that as great a difference in reference to the meteoric

conditions which determine the nature of climate, exists along the varying scale of longitude in either hemisphere, however imperceptible in the temperature,—as on that of latitude. And hence, as assumed, the source of the mystery which has so long involved the subject of climate, and which has baffled all the attempts hitherto made to ascertain its cause; as shown by the failure which, as in the case of the tea-plant, and others, has so frequently attended the attempts that have been made to introduce some of the products of certain countries, where, from the climate being considered the same, or better, it was supposed they would succeed equally well as in those of their nativity: this being a necessary consequence of the ignorance of principles. But as with the exception of the difference that occurs in the nature of the magnetic action of the sun on the opposite hemispheres of the earth, the same conditions of climate exist equally in both; but that from the difference in the sites of their magnetic poles, these conditions are, in regard to their positions, necessarily reversed to each other. Thus it is that, however diversified, and different in their positions, a common identity or sameness of climates exist in the opposite hemispheres; in this, that there is no climate in either,— as regards the circumstance of meteoric conditions; but that a similar climate may be found in the opposite.

And consequently there is no product of the animal or vegetable kingdom, however delicate, in either hemisphere, for which a suitable climate is not to be found in the opposite, equally adapted to its introduction as that where it was originally found and of which it is a native.

Thus as, according to the principle assumed, the chief source of error hitherto, in reference to climate, consisted in not having taken into account the cirumstance of longitude,-(or difference of magnetic action,) equally as of latitude, (or the difference of electric action,)-though a glance at the difference which exists between the products of the animal and vegetable kingdoms of the opposite extremes of the scale of longitude, within the same parallels of either hemisphere, as between those of latitude;―will immediately show, assuming it to be the cause, the extent of the influence on both, exercised by the former, equally as by the latter action of the sun. As connected with this subject, the following observation from the preface of an agricultural work, published in Dublin, 1764, by Mr. H. Rowlands, may be considered, from its novelty, as not a little curious; being, indeed, the only one bearing on the assumed connexion of magnetism with the constitution of plants, that I have met with, viz. "And probably it may also be a means to discover the proper subject of that noted magnetism, which is observed to lie in the substance of the mold, attracting into it in great