280 On Prussic Acid. {[ApRit, 
two salts combine, and form an insoluble. triple salt, composed: of 
one basis and two acids. It appears to me that in this case also the 
old doctrine accords with our other chemical opinions, 
(To be continued.) 
Articue VI. 
On a New Compound of Phosphorus and Potash. By the Chevalier 
Sementini, Professor of Chemistry at Rome. * 
Tue compound of potash and phosphorus remains stil] unknown. 
No mention is made of it in the modern books of chemistry ; and 
Klaproth, in his Dictionary of Chemistry, says frankly that * the 
science has not yet pointed out a mode of combining that substance 
with phosphorus.” 
I have obtained, for the first time, the phosphuret of potash by 
the following process :— 
1. I saturated very strong alcohol with potash. This solution had 
a deep amber colour 5 its consistence was, as it were, oily, and its 
taste very caustic. 
2. I introduced into this liquid pieces of phosphorus, which ap- 
peared instantly covered over with bubbles of gas. The phosphorus 
diminished in quantity, dissolving as this gas, which was a proto- 
phosphuret of hydrogen, was disengaged. When the first pieces 
were entirely dissolved, I introduced new ones ; and [ proceeded in 
this manner till all disengagement of gas was at an end, and till the 
phosphorus ceased to dissolve in the liquid. This saturation required 
at least 15 days. 
3. At the end of this first operation I found at the bottom of the 
vessel a powder of a dark red colour, and scales of a certain: bril- 
liancy, but covered with that powder. 
4. I separated the sediment of the liquid by the usual method of 
filtration ; and the liquid appeared to differ from the alcoholic solu- 
tion of potash by its straw colour; by its consistence, which was no 
longer oily, but fluid, like water; and by its taste, which had be- 
come sweetish and sharp. 
5. I dissolved the scales that remained on the filter in pure waters 
The solution was muddy; but, on being filtered, it became limpid, 
like water. 
6. There remained upon the filter a red powder, similar in ap- 
pearance to kermes mineral. 
7. The sides of the vessel in which the solution of the phosphuret 
had been made remained stained with black. 
* Translated from the Bibliotheque Britannique, Sept, 1815, vol. Ix. p. 24. 
