324 Sir H. Davy’s new experiments on some 
After reflecting much upon the methods of combining 
chlorine and phosphorus, so as to gain correct results, it 
occurred to me, that in operating over water, and introducing 
a perfectly saturated solution of chlorine to absorb the vapour 
of the sublimate and of its hydrate formed from the water 
in the chlorine, I should gain a result nearly correct. I made 
an experiment in this way on 4 grains of phosphorus, in a 
retort containing 13 cubical inches. I ascertained the absorp- 
tion, introduced into the retort a tube, containing about half 
a cubical inch of saturated solution of chlorine, and suffered 
the fluid slowly to act upon the sublimate, cooling the retort 
by immersion in water; I then ascertained the degree of the 
second absorption, which was nearly a cubical inch and a half. 
I likewise ascertained that water had its powers of dissolving 
chlorine diminished, and not increased, by uniting with phos- 
phoric and muriatic acids, so that the apparent absorption must 
have been less than the real one. Adding the second absorption 
to the first, and making the proper corrections, the quantity of 
chlorine uniting to 4 grains of phosphorus was 31.9 cubical 
inches; barometer being 30.1 inches, and thermometer 46° 
Fahrenheit. 
Rather a larger proportion would be given, if the correction 
for the presence of vapour had been made for some of the 
other experiments : and the result agrees exactly with the 
mean deduced from the absorption of oxygen in the formation 
of phosphoric acid ; for, assuming that 100 cubical inches of 
chlorine weigh 76.5 grains, then the sublimate will consist 
of 1 of phosphorus to nearly 6 of chlorine ; and taking the 
composition of phosphoric acid from this datum, it would 
consist of 100 of phosphorus and 135 of oxygen. 
