FORMS OF MATTER. 53 



produced biological phenomena, has committed liimself 

 to as wild a pursuit as he who rashly endeavours to catch 

 a morass-meteor. 



Subtile as are the forces of light, heat, and electricity 

 that of life, vitality, is infinitely more refined, and it 

 must for ever elude the search of the philosopher. 



Man is permitted to test and try all things which are 

 created, and to apply to useful ends the discoveries which 

 he may make. But man can never become a creator ; 

 and he who would attempt to give sense to an inert mass 

 of matter, by electricity, heat, or light, will prove him- 

 self as ignorant of nature's truth as is the senseless mass 

 upon which he works. 



"So far shalt thou go, and 110 further," was said 

 equally to the great tide-wave of human intellect, as to 

 the mighty surge of the earth-girdling ocean. 



It must not be forgotten that a striking difference 

 exists between the productions of the mineral and the 

 other kingdoms of nature. Animals and vegetables arrive 

 at maturity by successive developments, and increase by 

 the assimilation of substances, having the power of pro- 

 ducing the most important chemical changes upon such 

 matter as comes within the range of their influence ; but 

 minerals are equally perfect in the earliest stages of their 

 formation, and increase only, as previously said, by the 

 accretion of particles without their undergoing any 

 change. 



The animal and vegetable tribes cease to continue the 

 functions of life : death ensues, and a complete disorga- 

 nisation takes place; but this is not the case in the 

 mineral world : the crystal being the result of a con- 

 stantly acting force is not necessarily liable to decom- 

 position. 



Nevertheless, we sometimes find in nature that crys- 

 tals, after arriving at what may be regarded as, in some 

 sort, their maturity, are, owing to a change of the con- 



