THE ORIGm AND PROPAGATION OF DISEASE. 



A discourse lefore the Neiv York Academy of Medicine, ivith additions. 

 By John C. Dalton, M. D. 



The anniversary meeting of the Academy of Medicine may be regarded 

 as a sort of annual conference, in which one of its members is deputed 

 to offer to the Academy a short address upon some topic of general pro- 

 fessional interest, and more or less appropriate to the time. Perhaps 

 we can hardly employ the occasion to-night in a more suitable way than 

 by endeavoring to see what, on the whole, is the direction in which 

 medical thought is now most active; to cast the professional horoscope, 

 so to speak, for the present, and to anticipate, as nearly as may be, what 

 we are to expect from it in the immediate future. 



Not that we should be willing to claim the gift of prophecy or to place 

 too much confidence in delusive flights of the imagination. Medicine 

 is essentially a skeptical science, and very ijroperly regards with dis- 

 approval anything which claims her attention without offering, at the 

 same time, unmistakable guarantees of respectability. But there may be 

 a kind of anticipation which is really a scientific one. Within the past 

 two or three years we have seen our own Meteorological Bureau triumijh 

 over what was proverbially the most difficult of all popular j)uzzles, and 

 foretell the weather of each day with a certainty which has excited our 

 surprise and admiration. With telegraph-lines from all over the 

 continent converging to the central office at Washington, the chief 

 of the Bureau can trace, from hour to hour, the progress of a meteor- 

 ological change, moving, with uniform or accelerated speed, from Saint 

 Paul to Milwaukee, from Milwaukee to Detroit, from Detroit to Buf- 

 falo 5 and he knows that within a given period it will reach ISTew York, 

 with almost as much certainty as though he stood on the top of a watch- 

 tower and saw it coming. Within such limits as these it may perhaps 

 be allowable sometimes to indulge in surmises, even in the strictest and 

 most exacting of the natural sciences. 



Is there anything in the aspect and condition of any part of medicine 

 to-day that looks like a change in the scientific barometer ? Can we see 

 such a tendency in the medical mind at present as woukl suggest what 

 may fairly be callecl a new movement — in which successive ideas and 

 discoveries are not only accumulating as heretofore, but in which they 

 also seem to be taking, or about to take, a new interiDretation ; so as to 



