the Ai tra cl. ve Powers of Mineral Acids, 45 
Ikfis, wire!:. ; f :ed on by the vitriolic. This explana- 
tion i ceniwmoi by .he following experiments. 
Into 400 4 ;■ O: lpirit ot vitriol, whole fpecific gravity was 
1,362, I out 60 grs. of nitre. The thermometer fell from 68 
to 60, and during this time the nitrous acid was not expelled, 
for I put in fome filings of copper, and they were not in the 
lead: ached upon ; out in five minutes after, they viiibly effer- 
vefeed, which fhews that the nitrous acid began to be expelled. 
Again, to 400 grs of oil of vitriol, whofe fpecific gravity was 
1,870, 1 put 60 grs. of nitre : the thermometer immediately rofe 
from 68 to 105", and the nitrous acid was expelled in the form 
of a vifible fume. Thefe experiments prove, firft, that neutral 
falts are not decompofed, by mere folution, in an acid different 
from that which they poffcfs. 2dly, That the nitrous acid, 
being converted into vapour, had imbibed a large quantity of 
fire. But as the vitriolic, in both thefe experiments, w'as in 
much larger quantity than was neceffary to faturate the alka- 
line bafis of the nitre, I put 60 grs. of nitre into 64 of the 
above fpirit of vitriol, which contained the fame quantity of 
real vitriolic acid as the 60 grs. of nitre did of the nitrous, and 
added 40 grs. of water, and alfo a few grains of filings of cop- 
per. In lefs than two hours the copper was adted upon, and 
confequently the nitrous acid w 7 as expelled. 
Again to about 400 grs. of oil of vitriol, whofe fpecific gra- 
vity w r as 1,870, I put 100 grs. of common fait ; it immediately 
effervelced, and gave out the marineacid in the form of a wffite 
vapour. A thermometer held in the liquor rofe but 4 0 ; but: 
when placed in the froth it rofe to io°, and fell again on being, 
put into the liquor : whence it follows, that the vitriolic acid 
gave out its fire to the marine, and that this latter received 
more 
