The PREFAC E. iv 



As the art of Thyfick has of late years been 

 much improved by a greater knowledge of the 

 animal (economy \fo doubt lefs a fart her infight 

 into the vegetable economy mufl needs pro- 

 portionably improve our skill in Agriculture 

 and Gardening, which* gives mereafon to 

 hope, that inquiries of this kind will be ac- 

 ceptable to many, who are intent upon impro- 

 ving thofe innocent, delightful, and beneficial 

 Arts : Since they cannot be infenfible that the 

 mofi rational ground for Succefs in this lau- 

 dable purfuit mufl arife from a greater in- 

 fight into the nature of Plants. 



Finding by many Experiments in the fifth 

 chapter, that the Air is plentifully infpired 

 by Vegetables, not only at their roots, but 

 alfo thro' fever al parts of their Trunks and 

 Branches -, this put me upon making a more 

 particular inquiry into the nature of the Air-, 

 and to di f cover y if poffible, wherein its great 

 importance to the life and fupport of Vege- 

 tables might confijl ; on which account I was 

 obliged to delay the publication of the reft of 

 ihefe Experiments, which were read two years 

 fince before the Royal Society, till I had made 

 fome progrefs in this inquiry . An accou/nt of 

 which I have given in the (ixth chapter. 



i JVfiere 



