PREFACE. vii 



or inference, in connection with this subject ; 

 and while, I trust, credit has been given 

 wherever within my knowledge it is due, 

 my duty to the reader has compelled me 

 to point out where it has been unjustly 

 claimed or attributed. 



In constituting myself the historian of 

 this work — the commercial importance of 

 which cannot be realised for many years to 

 come, while its scientific interest is already 

 fully acknowledged — I desire to assume 

 the entire responsibility of the following 

 pages. 



A. N. 



London, May, 1882, 



