of the combinations of phosphorus. 329 
different combinations of phosphoric acid, for the purpose of 
ascertaining if they correspond with this number, 1 found 
the data so uncertain and so discordant, that it was impossi- 
ble to form any conclusions from them. The phosphate of 
soda, as is well known, has alkaline properties ; yet, accord- 
ing to M. Berzelius, it contains but 17.67 of soda to 20.33 
of acid ; whereas it ought to contain, according to the propor- 
tion indicated by my experiments (if neutral) nearly an 
equal weight of soda. M. Berzelius mentions several com- 
binations of baryta and lime with phosphoric acid, of which 
only two approach to a correspondence with the number I 
have given for phosphorus ; that containing 45.5 of acid 
to 48.7 of lime ; and that containing 39.1 of acid to 60.8 of 
barytes. New researches are required to explain the ano- 
malies presented by the phosphates. 
I shall give three experiments on the quantity of hydrate 
of potassa necessary for saturating given quantities of phos- 
phoric acid made from given weights of phosphorus. 
18 grains of phosphorus converted into phosphoric acid by 
combustion in oxygen, required for its saturation 47 grains 
of dry hydrate of potassa. 
5.7 grains of phosphorus converted into acid, required 14.7 
of hydrate of potassa. 
5 grains of phosphorus converted into perchloride, demand- 
ed, to produce perfect neutralization, 68 grains of hydrate of 
potassa. 
These three experiments agree so well with each other, 
and with the proportionate number gained from the absorption 
of chlorine and oxygen by phosphorus, that it is impossible 
not to put confidence in them. 
