fever, which depends essentially on a diminution and derangement of the formative process, as shown by the rapid emaciation that takes place during its progress, and which always terminates on the restoration of secretion and nutrition.

The truth is, that all constitutional diseases are owing to some alteration of the blood, and derangement of its vital properties, which are impaired by whatever seriously diminishes the functions of respiration, secretion, and nutrition. If the capillaries of the lungs be paralyzed by the inspiration of cold air, less carbon and hydrogen than usual are given off, less animal heat evolved, the temperature of the blood is reduced, its due arterialization prevented, its healthy properties so far deranged, as to diminish its power of uniting with the solids, and of maintaining the various secretions. The consequence of which is, a congestion of blood in the lungs; and if the latter state remain for any length of time, there is a stagnation throughout the systemic capillaries, so long as the chill continues. During this state, the atmosphere is kept at a moderate temperature, even during summer. But when the atmosphere is saturated with vapour, and its circulation ceases, as during the calm that precedes a thunder storm, the earth becomes feverish, (from an accumulation of caloric, which is no longer carried off in the combined state,) and oppressively sultry over large sandy plains, where there is no water. Besides, a large proportion of caloric is employed in the operations of universal chemistry, and the growth of vegetation, without which it would accumulate in the atmosphere in the free state, and render it oppressively warm.

the transition of caloric from blood to the solids
is greatly diminished. But as the function of
respiration, though greatly impaired, still con-
tinues to go on, the caloric thus evolved and
imparted to the blood, gradually raises its tem-
perature above the natural standard, by which
the action of the heart is augmented, until the
obstruction in the systemic capillaries is over-
come, and the superfluous caloric is transferred
to the solids, or carried off by the different
emunctories, when the fever subsides.

If the blood be not constantly depurated by
the elimination of sweat, urine, and other excre-
mentitious matters, its vital properties are im-
paired, and the springs of life vitiated at the
fountain head. For example, if there be 3lbs. of
water exhaled from the skin every twenty-four
hours, and perspiration be checked by exposure
to cold, the chemical and vital character of the
blood must be more or less changed, unless pre-
vented by a copious flow of urine. Or if the
amount of carbon and hydrogen exhaled from
the lungs be greatly diminished, as during the
cold stage of all maladies, the blood is no longer
renovated as in health, but becomes grumous
and dark coloured, and loses the power of uniting
with the various tissues. It has also been found,
that when the kidneys are extirpated, the ani-
mal is seized with difficult respiration, shivering,
coma, fever, vomiting, purging, typhoid symp-

resembles the return of venous blood to the heart. The deposition of sedimentary rocks from a state of solution in the water of lakes and seas, is also somewhat analogous to the process of nutrition, by which the composition of animals is renewed; while the removal of the effete portions of the body by absorption and elimination, is similar to the wearing away of mountains, hills, and elevated plains, by the corroding action of running water and chemical decomposition.

If then it be true, that the aggregate vital energy of animals and the development of their whole organization, are in proportion to the quantity of caloric they derive from the atmosphere by respiration, it must be the animating principle. Or if the faculty of sensation be annihilated by the abstraction of animal heat from the nervous system, it must be the sentient principle. And if the velocity of planets through their orbits diminish in proportion to their distance from the sun, it is self evident that their lasting motions would very soon come to an end, in the total absence of solar radiation. But as their centrifugal force is maintained by the perpetual radiation of caloric from the centre towards the circumference of the system, so is the centripetal force by which they are preserved in their respective orbits, maintained by the unceasing flow and pressure of the same great æthereal tide to the solar fountain from which it emanates.

Again, if it be true, as I have demonstrated, that the mobility and organizing power of matter are in proportion to the quantity of caloric around its atoms, and that these powers are diminished by every abstraction of caloric, or reduction of temperature; it follows, that in the total absence or privation of that principle, (if such a condition were possible,) the atoms of ponderable matter would be perfectly inert, and there could be no attraction, repulsion, contraction, and expansion of matter.

It was nobly said by Bacon, that "the highest ambition of man should be the discovery of some one thing by which all others might be discovered;" and that "science rightly interpreted, is the knowledge of things through their causes." Nor can there be a rational doubt, that a complete knowledge of the prime mover would afford a key by which to unloose the seals of the book of nature, and open the gates that lead to the inner temple of her most hidden mysteries. But owing to the paralyzing influence of custom, prejudice of education, and the dread of encountering the throned opinions of the world, few have had the boldness to inquire with unreserved freedom into the final cause of phenomena. The consequence of which has been, that the strength of many an intellectual giant has been wasted in fruitless efforts.

BOOK V.

CHAPTER I.

Influence of Climate and Season on the physical, intellectual, and moral Character of the Human Race, as shewn by the Difference of Stature, Magnitude of the Chest, Configuration of the Brain, Complexion, &c. among the Various Nations of the earth.

"If ever the science of life, and with it some of the most important departments of human knowledge, be destined to make any decided progress towards perfection, it must be by the road of experience, aided and enlightened by general philosophy." LAWRENCE.

NEXT to the discovery and developement of some grand truth capable of universal application to the benefit of mankind, the most important service that an author could bestow upon his species, would be to select from the vast accumulation of fabulous and contradictory statements that compose the mass of our printed books, whatever is really valuable. For, at present, the elements of knowledge are scattered over so broad a field,many of them are so imperfectly defined, and the truths already discovered are mingled with such a multitude of errors, that the best portion of