8 PREFATORY ADDRESS. 



The Author flatters hnnself, that his labours will be 

 found to open a field of experiment, of chemical rea- 

 soning, and of the praclically useful, appHcable to Agri- 

 culture, of Avhich that science has hitherto been thought 

 incapable. 



In the prosecution of his researches to so desirable an 

 end, he acknowledges the assistance he has derived from 

 the labours and valuable discoveries of a Priestley and a 

 Cavendish, under the heads of Air, or Gasses, Composi- 

 tion, and Decomposition of Water ; so true is the obser- 

 vation, that there is no art or discovery that is not the 

 parent or sister of some other. 



Gratitude requires that he should likewise acknow- 

 ledge the obligations he is under to his friend Mr. Van- 

 couver, for the time he has kindly dedicated, and the 

 relief he has afforded the Author in the fuigue of this 

 publication— a work wherein accuracy of chemical ex- 

 pression — a variety of important matter — attended with 

 the difRculty of distinft arrangement, never completely 

 to be attained in any work, where the subjefts to be 



treated 



