of the fixed Alkalies. 
c *9 
atmosphere, the moisture attracted rendered the results doubt- 
ful; and the proportions from the weight of the oxygene 
absorbed are more to be depended on. In the experiments in 
which the processes of weighing were most speedily per- 
formed, and in which no alkali adhered to the tube, the basis 
of potash gained nearly 2 parts for 10, and that of soda between 
3 and 4 parts. 
The results of the decomposition of water by the bases of 
the alkalies were much more readily and perfectly obtained 
than those of their combustion. 
To check the rapidity of the process, and, in the case of 
potash, to prevent any of the basis from being dissolved, I 
employed the amalgams with mercury. I used a known 
weight of the bases, and made the amalgams under naphtha, 
using about two parts of mercury in volume to one of basis. 
In the first instances I placed the amalgams under tubes 
filled with naphtha, and inverted in glasses of naphtha, and 
slowly admitted water to the amalgam at the bottom of the 
glass ; but this precaution I soon found unnecessary, for the 
action of the water was not so intense but that the hydrogene 
gas could be wholly collected. 
I shall give an account of the most accurate experiments 
made on the decomposition of water by the bases of potash 
and soda. 
In an experiment on the basis of potash conducted with 
every attention that I could pay to the minutiae of the opera - 
tions, hydrogene gas, equal in volume to 298 grains of mer- 
cury, were disengaged by the action of .08 grains of the basis 
of potash which had been amalgamated with about 3 grains 
of mercury. The thermometer at the end of the process 
