375 
the air, and a desire be expressed that he proceed in 
hi inquiries, he will yield a willing obedience to the 
imand j and, in a subsequent volume, will endea- 
to illustrate and explain the reciprocal effects 
:h are produced in the vegetable and animal 
ms. Though duly sensible of the difficulties 
which he has to encounter, he yet hopes to be 
able to present a view of these subjects, ade- 
quate, as he thinks, to explain the phenomena, and 
free from the objections which lie against every 
explanation that has been hitherto proposed. In fur- 
therance of this design, he now, therefore, ventures 
to announce his intention of attempting to trace all 
the observed effect sj which succeed to the exercise of 
the respiratory function in plants and animals, to the 
varied agency of that subtile or calorific matter, 
which is universally liberated, by the changes induc- 
ed on the air, during the continuance of this living 
process. 
