150 Dr. Pearson’s Experiments and Observations 
which was burst by the explosion and dispersed through the 
tube ; or else the quantity of water produced was so small, com- 
paratively with the residuary gaz, that the water was dissolved 
by it in the moment of its composition. For supposing water 
to have been compounded, it could not amount to the part 
of a grain ; and the residuary gaz was at least two thousand 
times this bulk. 
That a quantity of water can be compounded, under the 
same circumstances as in this experiment, and be apparently 
dissolved in air, so as to escape observation, even with a 
lens, was proved by passing an electric spark through a mix- 
ture of hydrogen and oxygen gaz, well dried by standing over 
lime. 
2. With complete or uninterrupted Discharges. 
The gaz obtained by the first described kind of apparatus, 
for the uninterrupted discharges, p. 145, and fig. 6 and 7, al- 
ways left a residue of at least one-fourth of its bulk on passing 
through it the electric spark; even when water was used, which 
had been freed from air by boiling, or the air pump. Nor will 
this result appear surprising, when it is considered how liable 
the water in this apparatus is to mix and absorb air during the 
experiment. However, this method would have been extremely 
valuable if the next other method had not been discovered; for 
gaz may be obtained b}^ it with fewer accidents, and much more 
rapidly, than with the interrupted discharges. The apparatus is 
also much more easily fitted up, and is more simple. But I 
think it unnecessary to particularly relate any experiments, as 
they afforded the same results as those already described, and 
as those next to be related. 
