the products of ignorance, unskilfulness, and even deceit, and hence that the simple truth seldom stands out clearly. The half-educated and the inexperienced observer or commentator is very apt to deceive others while he deceives himself. What he does not discern clearly he cannot make clear to others. A very significant phrase is attributed to Carlyle, to the effect that a teacher or writer "should learn to consume his own smoke." In this remark allusion was made to the noisy puffing of dark smoke by a steam engine before it begins its most efficient work; or, perhaps, to the ordinary chimney fire, that before it burns with a clear, glowing flame, sends forth volumes of smoke that fills the air and clogs the chimney. The simile is an apt one applied to inventors in mechanics, art, literature, or science, and especially to the young and inexperienced among them. In their eagerness to win fame they are tempted to parade their productions before a critical world and then, if their work is neglected or condemned, they are apt to feel surprise and, perhaps, resentment that the world failed to see their fire through the smoke they raised. But Carlyle's homely metaphor is only a variant of the Horation maxim Prematur in nonum. A nine years' gestation is often as necessary for a literary work as nine months are for a human progeny. It never deserved to be pondered more carefully than at the present day, when every fledgling in science or literature feels impelled to spread his wings for a flight toward the stars, too often forgetful of the melancholy fate of Icarus. But not only does immaturity of intellect produce abortions in science and art, but it also generates many that are feeble and incoherent rather than incomplete. A saying attributed to Napoleon is that "A general should indulge in no mental pictures, but look at things clearly, as through a field-glass," and this thought may be applied to observation in general. Concentration of attention is, first of all, essential to accuracy of vision; for if the thing observed is not clearly discerned its relation to other objects cannot be determined. So in natural science and in art the mind must, first of all, distinctly apprehend the thing that is to be studied, and after that its relation to associated things. So in medicine the only safe clue to an accurate conception of disease is through a minute study of all its forms and relations and the modifications they undergo through internal and external influences, and, next to those the variations imposed upon them by hygienic and therapeutic measures, i. e., by treatment.
We hear a great deal of "the advance of medicine," and are often reminded of discoveries made in human and comparative anatomy and
