VI PREFACE. 



hope of supplying the student of Nature with a 

 manual sufficiently comprehensive to serve as the 

 basis and foundation of more elaborate research. 

 In the treatment of our subject, we have sought, 

 as far as possible, to steer a middle course 

 between the two extremes of mere elementary 

 shallowness on the one hand, and scientific tech- 

 nicality on the other ; omitting, it is hoped, little 

 that will be deemed of importance by the general 

 reader, and at the same time studiously avoiding 

 such details as might be unintelligible, except to 

 the initiated. We have endeavoured, in short, to 

 comply as far as possible with the requisition of 

 our lady-friends, to write as much as possible 

 about what they do want to know, and as little 

 as possible about what they do not want to 

 know. How far we have succeeded in our task, 

 we leave to their merciful consideration. 



Athenaeum Club, 

 June 1858. 



