15 



session of common elements, but the relation of hardness to 

 condensation and the further relation of these qualities to 

 chemical indifference, constituted the basis for his classifica- 

 tion of mineral species. Whether amidst such a multitude 

 of individual species he, in his first arrangement, assigned to 

 each its proper place, may well be doubted, without question- 

 ing the substantial correctness of the principle on which his 

 chemical and natural-historical classification of minerals 

 rests. Yet it is impossible to follow, in his Systematic Miner- 

 alogy, the beautiful progressive series of quotients deduced 

 from the formula V = p -=- d (v being the coefficient of con- 

 densation; p the chemical equivalent, and d the specific grav- 

 ity) as calculated for the species under each genus, without 

 being convinced that Hunt heard and expressed one of those 

 wonderful harmonies of which it is granted to but few mor- 

 tals to catch the theme, amid the complexity and often 

 apparent discord of nature's contending voices. A very few 

 catch even an indistinct echo of one or another of the 

 motives which dominate the symphonies of nature ; but 

 fewer still hear and apprehend them so clearly as to be able 

 to write the score. The doctrine of the equivalency of 

 volumes, as applicable to liquid and solid species, as well as 

 to the gases on which is founded Hunt's Natural System of 

 Mineralogy, had dawned on his mind very early in his chemi- 

 cal studies ; but its larger significance was revealed to him 

 only toward the close of his life, when, though his physical 

 strength was waning his mental vision seemed to !. irainini: 

 boti. oneeption and wider range. To him the domain 



icmistrv was much wider than it had leeu held to be, 

 under the old conventional tlieorv. which drew such precise 

 lines between chemical and mechanical lorces. Like 

 philosophical chemists of to-day, lie regarded all solution a> 

 chemical union, and all chemical union as nothing else than 

 solution. In his view all precipitation and all crvstaili/.ation 

 1'rom solutions involve : change, ami all chemical 



.s mav theoretically exist in a dissolved state. tV,m 

 which they pass into polymeric mineral spe. insolu- 



