208 SCIENTIFIC THOUGHT. 



clopedias of the existing knowledge of nature, and celeb- 

 rities like Boerhaave, Linneeus, and Haller in more modern 

 times have been the living centres of all the natural 

 sciences. The same uniting bond has not been want- 

 ing in our century, when it has again, as many times 

 before, manifested its powerful influence, has brought 

 together researches which were on the point of fall- 

 ing asunder, and infused new life and interest into the 

 driest of studies. As I have had occasion to remark 

 above, the modern school of medicine originated in the 

 attempt — begun by Lavoisier in France, but carried out 

 on the largest scale in the chemical and physiological 

 laboratories of Germany — of making the new discoveries 

 8. in physical science and chemistry fruitful for medical 

 science purposcs and the treatment of pathological cases. The 



applied to 



medicine, discovcry of galvauism gave probably the earliest im- 

 petus, and was, to the discredit of an exacter treatment, 

 largely misused in the earlier part of the century, till 

 Du Bois Eeymond, in the middle of the period, based his 

 elaborate researches on more correct methods, and created 

 nearly all the knowledge we now possess of the electrical 

 currents in the nervous system. Somewhat earlier, Liebig 

 led the study of the phenomena of animal heat and of 

 the food relations of the animal and vegetable kingdom ; 

 the brothers Weber had introduced dynamics into the 

 theory of the motion of the heart and the limbs ; whilst 

 Johannes Miiller and his numerous school about the same 

 time laid the foundations of physiological and pathological 

 acoustics and optics. Quite independently of these appli- 

 cations of the mechanical and physical sciences, which led 

 some over-hastily to imagine that in the doctrine of the 



