PREFACE. Vll 
hand, nor, on the other, to convey in- 
accurate information. 
There are several popular works on 
this subject already before the public, 
hut none of them coincide with the 
above design. Kirby and Spence's In- 
troduction is a highly pleasing and sa- 
tisfactory book, but far beyond the com- 
prehension of the little students for 
whom this publication is intended. 
Mrs. Wakefield's Letters form a useful 
compendium, but, perhaps, too dry and 
cursory for the volatile minds of children. 
And in Joyce's Dialogues on the Micro^ 
scope, the descriptions are necessarily 
confined to those examples which suited 
his purpose. 
Such are the considerations which 
gave rise to this volume, and which 
encourage a hope, that it may prove, 
in some degree, a useful addition to 
the Juvenile Library. 
