Formation of Phosphuretted Hydrogen. 295 
water; bubbles arise and inflame upon contact of air, and 
they are phosphuretted hydrogen. Now in this case the ex- 
planation is very easy. Phosphorus cannot decompose wa- 
ter, and it must therefore be combined with a substance which 
has the power of doing this. Lime has not; calcinm has. 
Whatever of phosphuretted hydrogen, therefore, is produced 
in this way, must be ‘<a result of the action of phosphuret of 
ealcium, and not of |i 
Another method | is to put some pieces of phospho- 
rus into a retort filled with a solution of caustic potash, and 
to apply heat. In this case, the addition of heat enables the 
phosphorus to decompose the potash; a portion of it pro- 
bably unites with the oxygen of the alkali, forming an 
acid, another portion with its metallic base, forming a 
huret of potassium. This last decomposing the water, 
furnishes the. phosphuretted hydrogen. 
3. Instead of caustic potash, the carbonate of potash and 
quicklime are sometimes employed in combination with 
phosphorus, with the same results ; except that the evolution 
0 Phosphuresied hydrogen is not so rapid as in the former 
cases. rationale is, in effect, the same as before. The 
carbonic — of the carbonate of potash unites with the lime, 
and then the potash is acted upon by. the phosphorus in the 
manner above explained. 
If the above explanations be correct, we infer that for the 
production of phosphuretted hydrogen, it is only necessary 
to employ phosphorus and some metal, which metal, per se, 
= the property of decomposing water. 
e can, therefore, obtain this gas. 
= Frou the phosphurets of ALL the alkaline metals; as 
potassium, sodium, calcium, Bobs the mere addition of 
water. 
2. From a combination of phosphorus and the oxides of 
these metals ; as potash, soda, lime, &c. the application 
of a sufficient agp to enable the phosphorus to effect a decom- 
position of these o: 
3. From phosphorus and those metals which are usually 
employed in procuring hydrogen gas, as iron, zinc, &c. But 
as these o not decompose water with much rapidity, 
without the presence of some dilute acid, this must be added 
in the present case, and the process conducted in all respects 
as when we wish to obtain hydrogen alone, by means of these 
—The use of the acid in both cases is the same. _ 
i 
