332 LAUGEL'S PROBLEMS OF NATURE AXD LIFE. 



lines, betokening in each case the presence of some 

 element hitherto unseen by human eye. Nor without 

 this aid should we have learnt that lithium, before 

 deemed one of the rarest of metals, is diffused more 

 universally than almost any other in the organic as 

 well as inorganic matter of our globe ; attesting by this 

 RuTusion, however infinitesimally minute the quan- 

 tities concerned, some hidden use in the economy of 

 nature. 



From this method again we obtain further evidence, 

 were such necessary, of the inconceivable minuteness 

 of those atoms and molecules of matter which have 

 hitherto been subjected to the grosser processes of 

 chemical analysis. The detection, by its yellow spec- 

 trum-line, of less than a millionth part of a grain of 

 sodium in the air, is a striking instance in point ; and 

 many equivalent examples might be given. In truth, 

 this very minuteness of the ultimate parts the crcu/^ara 

 dSiaipera of matter, as well as their exquisite mobility, 

 if not indeed their unceasing motion, are necessary to 

 any conception we can form of the phenomena of the 

 material world. We must not here go aside to plunge 

 into the depths of the atomic theory, otherwise we might 

 add to these postulates that of determinate figure a 

 necessity, as we must regar4 it, of the functions they 

 perform the only key to the phenomena of definite 

 proportions, isomorphism, allotropy, and other facts and 

 doctrines embodied in chemical science. Adaptations, 

 perfect and constant such as these phenomena present, 

 can hardly co-exist but with forms equally perfect and 

 permanent. But admitting this, what system of atomic 



