240 Experiments on the Oxygenated 
of potash is equally harmless as common nitre; 
except it be brought into an intimate union with 
‘something that has a greater affinity with one of its 
constituent parts, than exists between those parts 
when combined in the salt, and that some combusti- 
ble substance be present: but .its oxygen being so 
easily disengaged, renders a little caution necessary; . 
and, as the sulphuric or nitrous acids seem so readi- 
ly to inflame many of the mixtures, I would not 
advise any person to make more of them than is 
necessary for immediate experiment. This pre- 
caution may prevent any unpleasant circumstance 
from accidental mixture with the acids, which ap- 
pear to disengage a great part of the oxygen al: 
most instantaneously. 
I shall not say much about the theory of these 
detonations, none of the foregoing experiments hav- 
ing been so carefully conducted as to determine 
accurately what changes took place; yet, I think, 
we may attempt to explain some of them in the fol- 
lowing manner. With phosphorus, the oxygen 
seems to combine, and form phosphoreous acid gas, 
or phosphoric acid: with sulphur, the sulphureous 
acid gas, or sulphuric acid, according to the rapidi- 
ty of the combustion: with charcoal and other ve- 
getable substances, the carbonic acid: with sulphu- 
ret of arsenic there may be sulphureous acid gas, 
and arsenic acid produced. 
The sudden production of gas striking the sur- 
