450 . New Experiments on some of 
entirely the hydrophosphoric gas, or phosphuretted hydrogen 
saturated with phosphorus. I say almost entirely, because in 
the beginning of the process, a little gas spontaneously inflam- 
mahle is produced, and a minute quantity of moisture appears : 
and when the heat is raised to redness, a very little phosphorus 
is produced, probably from the decomposition of a part of the 
phosphoric gas. Now supposing the quantity of phosphoric acid 
in phosphate of baryta known, and the quantity of phosphorus 
in phosphuretted hy drogen known ; it is very.easy, from an ac- 
curate experiment on the decomposition of the hypophosphite of 
baryta, to learn the composition of hypophosphorous acid. 
I made two experiments on this subject ; in one, 50 grains of 
dry hy pophosphite of barytes were used, and the distillation con- 
ducted in a small glass tube. About 23-25 cubical inches of 
gas were produced. The loss of weight of the apparatus could 
not be ascertained, as unluckily a little of the phosphate was 
lost ; asmall portion of phosphorus was deposited in the upper 
part of the tube, from the decomposition of a minute quantity 
of the bi-phosphuretted gas; but this could not have equalled 
the 4-10ths of a grain, as the tube only lost 4-10ths by being 
heated to whiteness. 
In the second experiment, 29 grains of the hypophosphite 
were used, and the Joss of weight only ascertained, which was 
3°5 grains. To be able to form any opinion as to the compo- 
sition of the hypophosphorous acid, it was necessary to ascer- 
tain the composition of the phosphate of baryta produced i in 
these experiments ; which was easily done by precipitating a 
given quantity of the hypophosphite of barytes by sulphate of 
soda in solution. Fifteen grains of hypophosphite of barytes, 
in an experiment very carefully made, afforded 11:3 of sulphate 
of barytes. Now, supposing this sulphate of barytes to contain 
7-4 of baryta, the hypophosphite would consist of 7*4 of ba- 
ryta, and 7°6 of hypophosphorous acid; and 13:1 of the acid 
phosphate of baryta, formed from its decomposition, would 
contain 5-7 phosphoric acid, and 7°4 baryta. And in the expe- 
riment in which 29 grains of hypophosphite of baryta were de- 
composed, supposing the whole loss of weight to be owing to 
perphosphuretted hydrogen given off, and this gas to be com- 
posed of 22:5 of phosphorus to 4 of hydrogen, or of 5°29 hy- 
drogen to 29-76 phosphorus, and the 25:5 of acid phosphate 
remaining composed of 14:47 baryta nearly, and 11°03 phos- 
phoric acid, adding the 29°76 of phospbaray to the 4°72 in the 
phosphoric acid, and subtracting 39, the quantity of oxygen 
required to form water with the 5: 24. of hydrogen, the hypo- 
phosphorous acid may be conceived to be composed of 7°69 
phosphorus, 
