100 



THE ADVANCE OF SCIENCE 



other The execution of my further task, the 



ticliicv6~ 



ments in indication of the most important achieve- 

 science! 1 ments in the several branches of physical 

 science during the last fifty years, is em- 

 barrassed by the abundance of the objects 

 of choice ; and by the difficulty which 

 everyone, but a specialist in each depart- 

 ment, must find in drawing a due distinc- 

 tion between discoveries which strike the 

 imagination by their novelty, or by their 

 practical influence, and those unobtrusive 

 but pregnant observations and experi- 

 ments in which the germs of the great 

 things of the future really lie. Moreover, 

 my limits restrict me to little more than a 

 bare chronicle of the events which I have 

 to notice. 



In physics and chemistry, the old 

 boundaries of which sciences are rapidly 

 becoming effaced, one can hardly go wrong 

 in ascribing a primary value to the inves- 

 tigations into the relation between the 

 solid, liquid, and gaseous states of matter 



Physics 

 and 



chemis- 

 try. 



