PREFACE. XI 



As for himself, though the compilation of these 

 pages has involved unremitting literary labour, of 

 many years' duration : the Author can only say, 

 the work to him has been a labour of love; and 

 he parts from it upon its completion, as from an 

 old and valued friend his constant companion 

 for years. The numerous references to the works 

 of other authors, some of which will be found on 

 almost every page, will give some idea of the 

 variety and extent of the research which has been 

 necessary to obtain what seemed to be the best 

 and most valuable information, on the different 

 points discussed. The Author has in all cases, 

 wherever possible, always endeavoured to fortify 

 his own opinion by quoting that of other writers, 

 who may have made special studies of the different 

 branches of literature or of science, which may 

 have been touched upon; in order that where he 

 has erred, he may, so to speak, do so in good 

 company, and after consulting the best authorities 

 extant. The fallibility of the human understanding 

 has constantly been recognised by all who have 

 given close attention to the examination of natural 

 phenomena, but it is only when the student comes 

 to seek for facts relative to some of the matters 

 treated of in these volumes, that he becomes aware 

 of the paucity of observations which have been 

 recorded about them in books, and how little is 

 really known about such things. 



It will be observed that the Author has gener- 

 ally avoided speaking of himself. Egotism, in 

 treating of such subjects, has seemed to him 

 both unnecessary and unbecoming, as well as 



