“I have no doubt,” says this practitioner, “that any physician who will carefully attend to the diurnal and nocturnal returns of the tides, and will constantly hold before him the prevailing tendency of fevers to appear at the commencement, and during the period of the spring; and to subside and terminate at the commencement and during the period of the recess, will soon obtain more information respecting the phenomena of fevers, and he able to form more just and certain judgements and prognostics respecting every event, than if he were to study the history of medicine, as it is now written, for a thousand years. There is no revolution or change in the course of fevers that may not be explained by these general principles in a manner consistent with the laws of the human constitution, and of the great system of revolving bodies which unite together in producing them.” Dr. Balfour spared no pains in collecting information to elucidate and confirm his theory during the course of thirty years practice in India. He communicated upon it with most of the European practitioners in the Company's dominions; and the then Governor General, Lord Teignmouth, considered the subject as so important, that he properly as well as liberally ordered the correspondence and the treatise, in which its results were embodied, to be printed and circulated at the expense of the government. The author drew up his scheme of an Astronomical Ephemeris, for the purposes of Medicine and Meteorology, and satisfied himself that he had “discovered the laws of febrile paroxysms,” and unfolded a history and theory of fevers entirely new, consistent with itself in every part, and with the other appearances of nature, perfectly conformable to the laws discovered by the immortal Newton, and capable of producing important improvements in medicine and meteorology. He protested against objections to his theory as if it were connected with the wild and groundless delusions of astrology. Yet the letter of his correspondent, Dr. Helenus Scott, of Bombay, shews how naturally and inevitably it would be connected with them in that country. “The influence of the moon on the human body,” says that physician, “has been observed in this part of India by every medical practitioner. It is universally acknowledged by the doctors of all colours, of all casts, and of all countries. The people are taught to believe it in their infancy, and as they grow up, they acknowledge it from experience. I suppose that in the northern latitudes this power of the moon is far less sensible than in India. Here we universally think that the state of weakly and diseased bodies is much influenced by its motions. Every full and change increases the number of the patients of every practitioner. That the human body is affected in a remarkable manner by them I am perfectly convinced, and that an attention to the power of the moon is highly necessary to the