Another great change in modern practice is specialization.  Perhaps it has not yet reached the delicate particularity of the practice in ancient Egypt, where every minute part of the human economy had its exclusive doctor.  This is inevitable in a scientific age, and the result has been on the whole an advance of knowledge, and improved treatment of specific ailments.  The danger is apparent.  It is that of the moral specialist, who has only one hobby and traces every human ill to strong liquor or tobacco, or the corset, or taxation of personal property, or denial of universal suffrage, or the eating of meat, or the want of the centralization of nearly all initiative and interest and property in the state.  The tendency of the accomplished specialist in medicine is to refer all physical trouble to the ill conduct of the organ he presides over.  He can often trace every disease to want of width in the nostrils, to a defective eye, to a sensitive throat, to shut-up pores, to an irritated stomach, to auricular defect.  I suppose he is generally right, but I have a perhaps natural fear that if I happened to consult an amputationist about catarrh he would want to cut off my leg.  I confess to an affection for the old-fashioned, all-round country doctor, who took a general view of his patient, knew his family, his constitution, all the gossip about his mental or business troubles, his affairs of the heart, disappointments in love, incompatibilities of temper, and treated the patient, as the phrase is, for all he was worth, and gave him visible medicine out of good old saddle-bags—­how much faith we used to have in those saddle-bags—­and not a prescription in a dead language to be put up by a dead-head clerk who occasionally mistakes arsenic for carbonate of soda.  I do not mean, however, to say there is no sense in the retention of the hieroglyphics which the doctors use to communicate their ideas to a druggist, for I had a prescription made in Hartford put up in Naples, and that could not have happened if it had been written in English.  And I am not sure but the mysterious symbols have some effect on the patient.

The mention of the intimate knowledge of family and constitutional conditions possessed by the old-fashioned country doctor, whose main strength lay in this and in his common-sense, reminds me of another great advance in the modern practice, in the attempt to understand nature better by the scientific study of psychology and the occult relations of mind and body.  It is in the study of temper, temperament, hereditary predispositions, that we may expect the most brilliant results in preventive medicine.