[ liii ] 



Explication offome "Technical Terms* 



A S this volume may poffibly fall 

 into the hands of fome who have 

 not yet read the works of Dr. 

 Prieftley, and are entirely ftrangers 

 to the new doctrine of air ; I think 

 it will be ufeful to explain the 

 meaning of the new invented names 

 given to different kinds of air men- 

 tioned in this book. 



Nitrous air is that kind of per- 

 manent elajlic fluid which is ex- 

 tracted by nitrous acid or aqua 

 fortis from the mofl part of metals, 

 principally from mercury, brafs, 

 copper, &c. This air is by a 

 bended glafs tube conducted under 

 d 3 an 



