BOOK IV. CHAPTER I. Life. "First then, if any one think that the secrets of nature remain shut up, as it were with the seal of God, and by some divine mandate interdicted to human wisdom, we shall address ourselves to remove this weak and jealous notion; and, relying on simple truth, shall bring the inquiry to this issue, not only to silence the howl of superstition, but to draw religion herself to our side." BACON. WHETHER in a theoretical or practical point of view, the animating principle is the most important problem that ever engaged the attention of mankind; for it connects all that is profound and fascinating in physics, with the science of preserving health and prolonging life. Never can the healing art take its appropriate rank among the exact sciences until the cause of vital force and animal motion is distinguished from the operations which it produces; but must remain, as in all the ages that are past, a mere collection of empirical rules. If it be true that every deviation from health is immediately connected with some derangement of the vital principle, there cannot be a doubt, that a clear comprehension H H of what it is, and of the laws by which it operates, would do more to meliorate the condition of mankind, than all the systems that have been invented from the age of Hippocrates to the present time; because it would lead, not only to a certain method of curing diseases, but, what would be of vastly greater consequence, the theory of life would become intelligible to all; and its chief glory would be the prevention rather than the cure of maladies. The whole object of medical science is to regulate the forces of life-to increase them when and where they are deficient-to restrain them when excessive-and to restore their natural balance when deranged. But how can we know the best means of maintaining the functions of life in a healthy state, while ignorant of the physical cause on which they all depend? How is it possible to counteract with certainty, those involuntary movements that constitute tetanus, hydrophobia, and other forms of convulsive disease, without knowing the cause of muscular contraction in a state of health? How can we adopt the best treatment of fever, inflammation, and the various species of malarious affections, without comprehending the true theory of animal heat, and the specific office which it performs in the economy of life? Why are so many diseases pronounced incurable, though attended with no organic lesion, and ranked among the opprobria |