SULPHURIC ACID AND WATER. 291 
vitriol + 3 water.) The mercury rose from 51° 
to 256°, = an increase of 205° of temperature. 
The experiment being reversed, the mercury. 
rose from 51° to 258°, = an increase of 207° 
of temperature. 
EXPERIMENT IV. 
424.8 grains of the concentrated vitriol were 
poured to 312 grains of water (= 1 atom oil of 
vitriol + 4 water.) The mercury rose from 45° 
to 234°, = an increase of 189° of temperature. 
The experiment being reversed, the mercury 
again rose from 45° to 234°, = an increase of 189° 
of temperature. 
In making these experiments, care was taken 
that the vitriol and the water were of the same 
temperature as the glass in which they were to 
be mixed and the thermometer, all having been 
allowed to stand in the same situation for a con- 
siderable time. The liquid which had to be 
poured to the other, was poured from a bottle 
having a wide neck, in which it was weighed pre- 
viously : that which was to have the other poured 
to it, was weighed in the cup in which the mix- 
ture was to be effected. The same vessels and 
