“‘Might not some other cause,’ said I, ’produce this concurrence?  The Nile does not always rise on the same day.’

“‘Do not believe,’ said he, with impatience, I that such objections could escape me:  I reasoned long against my own conviction, and labored against truth with the utmost obstinacy.  I sometimes suspected myself of madness, and should not have dared to impart this secret but to a man like you, capable of distinguishing the wonderful from the impossible and the incredible from the false.’

“The good old astronomer gives his parting directions to Imlac, whom he has adopted as his successor in the government of the elements and the seasons, in these impressive words: 

“Do not, in the administration of the year, indulge thy pride by innovation; do not please thyself with thinking that thou canst make thyself renowned to all future ages by disordering the seasons.  The memory of mischief is no desirable fame.  Much less will it become thee to let kindness or interest prevail.  Never rob other countries of rain to pour it on thine own.  For us the Nile is sufficient.’

“Do you wonder, my friends, why I have chosen these passages, in which the delusions of an insane astronomer are related with all the pomp of the Johnsonian vocabulary, as the first lesson for the young person about to enter on the study of the science and art of healing?  Listen to me while I show you the parallel of the story of the astronomer in the history of medicine.

“This history is luminous with intelligence, radiant with benevolence, but all its wisdom and all its virtue have had to struggle with the ever-rising mists of delusion.  The agencies which waste and destroy the race of mankind are vast and resistless as the elemental forces of nature; nay, they are themselves elemental forces.  They may be to some extent avoided, to some extent diverted from their aim, to some extent resisted.  So may the changes of the seasons, from cold that freezes to heats that strike with sudden death, be guarded against.  So may the tides be in some small measure restrained in their inroads.  So may the storms be breasted by walls they cannot shake from their foundations.  But the seasons and the tides and the tempests work their will on the great scale upon whatever stands in their way; they feed or starve the tillers of the soil; they spare or drown the dwellers by the shore; they waft the seaman to his harbor or bury him in the angry billows.

“The art of the physician can do much to remove its subjects from deadly and dangerous influences, and something to control or arrest the effects of these influences.  But look at the records of the life-insurance offices, and see how uniform is the action of nature’s destroying agencies.  Look at the annual reports of the deaths in any of our great cities, and see how their regularity approaches the uniformity of the tides, and their variations keep pace with those of the seasons.  The inundations of the Nile are not more certainly to be predicted than the vast wave of infantile disease which flows in upon all our great cities with the growing heats of July,—­than the fevers and dysenteries which visit our rural districts in the months of the falling leaf.