VI PREFACE. 



last, therefore, rest at present upon authority 

 alone. 



In this essay I have ventured to state some 

 of the arguments, which seem, to my judgment, 

 fatal to all physical hypotheses of life, and 

 have adduced a few of the most important 

 facts and observations, which have led me to 

 advocate a very different conclusion. 



GROSVENOR STREET ; 



Febmary, 1871. 



