xxiii 



PREFACE 



TO THE 



SECOND EDJTION. 



THE favourable reception the firft edi- 

 tion of this work has met with 

 from the public, animates me in the 

 ftrongeft manner to render the prefent 

 impreilion as perfect as pomble. I have 

 corrected it with as much attention as I am 

 able ; and applied, I believe, to every 

 perfon whofe experiments are mentioned, 

 for their corrections, and the continuation 

 of their trials, and am happy in being able 

 to infert many fuch improvements that 

 render the refpective regifters much more 

 iifeful than they would otherwife be. The 

 communications of this fort which I have 

 B b eon 



