'Formation of nitrous Acid. 
In order to difcover how nice a teft of alcalinity the paper 
tinged with blue flowers was, a faturated folution of com- 
mon nitre was mixed with ^ of its bulk of the foap-lees ; 
and this mixture was found to turn the paper evidently green ; 
lo that, as the folution of nitre contains about twice as much 
alkali as the foap-lees, it appears, that if the reflduum had 
wanted only part of being faturated, it would have difco- 
loured the paper. 
from the foregoing trials it appears, that the mixture of 
dephlogifticated and common air in this experiment was actually 
converted into nitrous acid, and was fufficient not only to fa- 
turate the foap-lees, but alfo to diflblve fome of the mercury. 
The quantity diflolved, however, was very fmall, and not fuf- 
ficient to diminifh fenfibly the deflagrating quality of the ni- 
tre; fo that the proof of the air being converted into ni- 
trous acid was as evident as if no mercury had been diflolved. 
In this experiment, as well as the former, no indication of 
the foap-lees becoming faturated was afforded by any ceflation 
in the ditninution of the air ; whereas, in my experiments, it 
was very manifefl. I do not know what this difference fhould 
be owing to, except to Mr. Gilpin’s giving much flronger 
electrical fparks than I did. In his experiments the metallic 
knob which received the fpark, and conveyed it to the bent 
tube, was ufually placed at about 2\ inches from the con- 
ductor, fo that the fpark jumped through 2\ inches of air, in 
paffing from the conductor to the knob, befides from i \ to 21- 
inches of air in the tube ; whereas in my experiments, I be- 
lieve, the knob was never placed at the diftance of more than 
ij inch from the conductor, and the quantity of air in the 
tube was much lefs ; but the conductor and eleCtrical machine 
were the fame. 
O02 
Except 
