in, by successive inhalations, all the fresh air possible, and pressing it down to the lowest depths of the lungs. This process at first gave such intensity and sharpness to the pain in the head, that it required much resolution to continue it; nevertheless it was persevered in. After a few minutes, the pain diminished, and soon entirely ceased. This was followed by free perspiration, and equalized, warmth and circulation. Perfect repose and quiet sleep ensued. Friends, who a short time before had seen a countenance like that of a dying person, and knew how slow was ordinary cure, were astonished, an hour afterwards, to behold, on my awaking, the full glow of restored health.[6] On the re-appearance of cholera, during the summer of 1849, my mind was peculiarly affected, from the belief that a false theory of circulation prevailed, although there was a true theory, which, if generally believed, might lead to the knowledge of the cause and cure of this terrific malady; and thus thousands of lives be saved which would otherwise be lost. This thought almost distracted me; and believing that my sex stood in the way of my theory's being acknowledged, I sometimes wished that it might please God to take me out of the world. Then coming to better thoughts; I cast away despondency as unworthy of me; and determined to proceed to the further investigation and development of the great truth, of which I had, as I believed, been made the unworthy recipient. I studied my theory anew, while I read the most approved works on cholera; and I came to the belief that imperfect respiration, caused by the want of due oxygen in the air, was the principal predisposing cause of the premonitory symptoms; while the death that supervened was often caused by the settling of carbonic acid gas, the residuum of animal combustion, in the lower air-cells of the lungs. The symptoms of the cholera, as treated by the best writers, were full of new proofs of the truth of my theory, especially of its last step, the formation of steam or vapor in the lungs. Without that, the collapse of cholera was a fearful mystery; with it, everything was plain. With a coldness that would collapse the lungs, the bowels must naturally be drawn up (and with dreadful pains) to supply their place. The ghastly change in the face must occur when cold has condensed its arterial vapor. If respiration could restore heat, before any lesions had taken place in the organism, the patient might recover. Then I began rewriting my theory in a work afterwards published, with the title, "Respiration and its Effects, especially in relation to Asiatic Cholera and other Sinking Diseases."