f 98 J 
having feen many more tried by 
Abbé Fontana, I no longer made the 
feaft doubt, but the difcovery of 
Dr. Prieftley in judging of the ex- 
aét degree of goodnefs of any air 
was Without any exception. But, 
as I was refolved to abftain as much; 
as poffible from all analogical con- 
clufions, without they were fup- 
ported by direct experiments, I tried 
every air I could find, not only by 
the nitrous teft, but alfo by the 
flame of a candle, without, how- 
ever, harbouring any miftruft in the 
already adopted manner of examin- 
ing the degree of goodnefs of them. 
I had already been convinced, 
that inflammable air was made ex 
plofive in a few hours when expofed 
in the fun with any plant, though 
I fometimes found it, by the nitrous 
teft, fo much corrected as to ap- 
