12 REPORT— 1893. 



beeu. left over by his predecessors are of extreme difficulty, all of tbe 

 easier questions having been worked out. There were then also difficul- 

 ties, but of an entirely different kind. The work to be done was in itself 

 easiei", but the means for doing it were wanting, and every investigator 

 had to depend on his own resources. Consequently the successful men 

 were those who, in addition to scientific training, possessed the ingenuity 

 to devise and the skill to carry out methods for themselves. The work 

 by which du Bois-Reymond laid the foundation of animal electricity 

 would not have been possible had not its author, besides being a trained 

 physicist, known how to do as good work in a small room in the upper 

 floor of the old University Building at Berlin as any which is now done 

 in his splendid laboratory. Had Ludwig not possessed mechanical apti- 

 tude, in addition to scientific knowledge, he would have been unable to 

 devise the apparatus by which he measured and recorded the variations 

 of arterial pressure (1848), and verified the principles which Young had 

 laid down thirty years before as to the mechanics of the circulation. 

 Nor, lastly, could Helmholtz, had he not been a great deal more than a 

 mere physiologist, have made those measurements of the time-relations of 

 muscular and nervous responses to stimulation, which not only afford a 

 solid foundation for all that has been done since in the same direction, 

 but have served as models of physiological experiment, and as evidence 

 that perfect work was possible and was done by capable men, even when 

 there were no physiological laboi-atories. 



Each of these examples relates to work done within a year or two of 

 the middle of the century.' If it were possible to enter more fully on the 

 scientific history of the time, we should, I think, find the clearest evidence, 

 first, that the foundation was laid in anatomical discoveries, in which it 

 is gratifying to remember that English anatomists (Allen Thomson, 

 Bowman, Goodsir, Sharpey) took considerable share ; secondly, that 

 progress was rendered possible by the rapid advances which, during the 

 previous decade, had been made in jjhysics and chemistry, and the partici- 

 pation of physiology in the general awakening of the scientific spirit 

 which these discoveries produced. I venture, however, to think that, 

 notwithstanding the operation of these two causes, or rather combinations 

 of causes, the development of our science would have been delayed had it 

 not been for the exceptional endowments of the four or five young experi- 

 menters whose names T have mentioned, each of whom was capable of 

 becoming a master in his own branch, and of guiding the future progress 

 of inquiry. 



Just as the affinities of an organism can be best learned fi'om its 

 development, so the scope of a science may be most easily judged of by 



' The UnteTsuclnmgen iiher ilnerische EleotrieUat appeared in 1848 ; Ludwig's 

 researches on the circulation, which included the first description of the ' kymo- 

 graph ' and served as the foundation of the ' graphic method,' in 1847 ; Helmholtz's 

 research on the propagation in motor nerves in 1851. 



