Theory of Circulation by Respiration | Page 4

sufficient, of itself, to produce a current as rapid as that of the blood was proved to be, even on the lowest estimate of its velocity. This did not shake my faith in the great fact that circulation was created by respiration. It must be so; for in life, such respiration as produces heat is the invariable antecedent of circulation, and nothing else is. There was something, then, which remained to be discovered. Again, I placed before me the conditions of the great problem, and set myself intently to its study; and I soon found what I thus sought, and then discerned for the first time that the blood moves, as does the railroad car, by steam. John Bell, my favorite author, had shown that the lungs work in vacuo. A great proportion of the blood is water, which, in a vacuum, springs into vapor at 67��, and the temperature of the blood in the lungs is 101��. Its expansion, then, was not merely the gradual increase of bulk by transmitted heat, but also that of instantaneous expansion, by the vaporization of so much of it as is needed; and what expanded water could not do, steam certainly could. At once, a throng of proofs came to my mind. The most apparent of these was the vapor expired breathing. I recollected how, in former times, the stage horses, driven rapidly into my native village of a winter morning, had clouds of vapor wreathing upward from their nostrils, while the icicles of condensation were hanging below. The nurse, who stands over the dying, holds a mirror before the mouth and nose, and considers that life is only extinct when vapor ceases to be formed. Then came to mind the solution of that great mystery of physiology, why the arteries are empty at death, which so long hindered the discovery finally made by Harvey.
In the state in which chemistry was, even as late as the time of John Bell, the chemical power of the heat produced by respiration at the lungs could not have been understood.
SECTION II.
Publication of the Theory, in 1846, in "A treatise on the Motive Powers which produce the Circulation of the Blood." Its Reception: Critique in the New York "Journal of Medicine," September, 1846. My Reply, in the same Journal, March, 1847.
TO DR.?MARCY.--In the years immediately succeeding 1840, (in which year, as you will recollect, I had the honor to receive your countenance and advice respecting my theory,) I was almost exclusively devoted to the revision and enlargement of my historical works; but early is 1846, having determined on making the tour of the United States, I resolved first to prepare my theory for the press. In the introduction, I remarked, "The house of clay in which the mind dwells must receive a portion of its care; and that which I have bestowed on mine has proceeded on a belief in the truth of the theory herein advocated, as undoubting as that in the laws of gravitation; and when any new fact, or any remark of an author, relating to my theory came under my observation, I noted it down and laid it by with its kindred. About to set out on a long journey, and aware that my field of vision had thus enlarged, I felt it my duty to put together the principal of my remarks, that I might so leave the subject, that, in case anything should prevent my return, it would be in a form equal to the present slate in which the theory exists in my own mind."
The time I had spent in devotion to this theory, the many rebuffs I had met in seeking to promulgate it--sometimes, unhappily, affecting my social life--had made painful the duty of publishing it. My historical works had been received with favor; but I believed that, in publishing this, it would be charged against me that I chose a subject unsuited to my sex. I therefore said, in my preface, "This is not so much a subject which I chose, as one which chooses me; and if the Father of Lights has been pleased to reveal to me from the book of his physical truth a sentence before unread, is it for me to suppose that it is for my individual benefit? or is it for you, my reader, to turn away your ear from hearing this truth, and charge its great Author with having ill-chosen his instrument to communicate it?"
As I passed southward on my journey, I left, March, 1846, my manuscript in the hands of Wiley & Putnam, in N. York:[4] to be published at my expense. During the six months in which I was absent on my travels, my book was published; and the publishers sent copies, as directed by me, to many of