Sir H. Davy’s new experiments on phosphorus. 317 
following pages, will serve to correct and fix, I hope, with 
tolerable accuracy, the proportional number or equivalent of 
phosphorus, and at the same time will show the truth of the 
general series of proportions that I assigned to its compounds 
In a case where my conclusions differ so materially from those 
of M. Berzelius and Dulong, it may be supposed that I 
have not adopted them without considerable caution ; and I 
have preferred my own results to theirs, only because they 
have been confirmed by minute and repeated experiments. 
I was certain from various experiments, made both long ago 
and recently, and the results of which had been confirmed by 
Mr. Brande, that the proportion of oxygen, which M. Dulong 
assigns to phosphoric acid, is considerably smaller than that 
denoted by the combustion of small quantities of phosphorus 
in oxygen gas. I knew that minute portions of phosphuretted 
hydrogen were separated from phosphorus by voltaic electri- 
city ; and it occurred to me as possible, that water might be 
formed in the combustion of phosphorus, and separated from 
the phosphoric acid when it entered into saline and metallic 
combinations. To ascertain if this were the case, I passed 
phosphorus to saturation through red hot lime in a green 
glass tube connected with a mercurio-pneumatic apparatus : 
the combination took place with vivid ignition ; but no elastic 
fluid was produced. A portion of the phosphuret of lime 
formed, was introduced into a tray of platinum, and heated in 
a glass retort filled with oxygen gas ; the phosphuret of lime 
burnt brilliantly, and became partly converted into phosphate 
of lime; but on restoring the original temperature of the retort, 
there was no appearance of vapour or of moisture. 
Having examined the phosphate of lime formed in this 
