158 VIGNETTES FROM INVISIBLE LIFE. 



thousand additional beauties of structure or en- 

 gravings on them are revealed. They will bear 

 any amount of amplification ; and the more they 

 are scrutinized, the more beautiful and exquisite 

 the markings are seen to be. 



Grems and jewels suggest the ideas of rarity 



FIG. 26. Diatoms. 



and preciousness, but only the latter term applies 

 to these, for not only are they not rare, they are, 

 on the contrary, the most numerous and the most 

 widely diffused of all material objects ; and that they 

 are costly or precious can only be inferred or de- 

 clared of them when their functions, their formation, 

 and the offices they perform in the general economy 

 of nature, are understood. They are then seen to 



