282 New Compound of Phosphorus and Potash. (Apri, 
phosphuret of potash of the greatest part of its alkali; and the two 
liquids are converted into a gelatinous mass, which is a mixture of 
sulphate of potash and super-phosphuret of potash. This mixture, 
when heated till it becomes dry, exhibits the important phenomenon 
of the complete decomposition of sulphuric acid; a result which 
cannot be obtained completely by any other agent than phosphorus. 
From this decomposition it comes to pass that the heated mass, 
before it be guite dry, acquires a yellow colour from the sulphur 
disengaged. ‘This sulphur is gradually dissipated in the state of 
vapour. The saline matter resulting from this decomposition is 
phosphate of potash. 
Muriatic acid poured into the liquid occasions the precipitation of 
muriate of potash, which cannot be separated from a certain quantity 
of phosphuret of potash that remains combined. Hence when the 
mixture is heated it takes fire, in consequence of the portion of 
phosphuret of potash which it contains. 
Nitric acid produces neatly the same effect on the liquids of Nos. 
4and5. ‘The nitrate of potash which is formed crystallizes pretty 
rapidly, and is deposited at the bottom of the liquid. When en- 
tirely separated from the supernatant liquid, and strongly heated, it 
produces the same effects as common nitre. But if the mixture of 
liquid and salt be heated till it becomes dry, one of the most violent 
and dangerous detonations takes place to which we are exposed in 
chemistry. The experiment must be made upon a very small quan- 
tity of matter, otherwise the danger will be serious. Not being 
aware of the effect, I evaporated to dryness about 36 grains of the 
salt mixed with the liquid. The detonation was so violent as to 
drive me to the ground, quite confused; and I remained deaf 
during a whole day. Every thing brittle on the table of the labo- 
ratory was broken to shivers. Considering the small quantity of 
matter capable of producing such an effect, I conceive that this 
substance, next to detonating silver, is the most violent with which 
‘we are acquainted. 
The phenomena which I have described are doubtless entitled to 
a more accurate examination, and I propose to study them more in 
a set of experiments which | intend to undertake ; hoping that in 
the mean time I shall receive such information from those chemists 
who are interested in the subject as will enable me to advance fur- 
ther in that inquiry. 
P.S. I afterwards found a more convenient mode of obtaining 
phosphuret of potash. tis as follows :—Form a saturated solution 
of potash in water. Add pieces of phosphorus. No reciprocal} 
action takes place ; but when highly rectified alcohol is added, a 
lively effervescence immediately takes place, and proto-phosphureted 
hydrogen gas is evolved in abundance. ‘The phosphorus dissolves 
with the same rapidity at the commencement of the operation, bus 
more slowly afterwards. ‘The phenomenon does not proceed from 
the small elevation of temperature produced by the mixture of the 
aleckol with the water ; for when potash and phosphorus are heated 
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