ACTION OF PIIOSPHOJIUS ON ALKALt<f. OOy 



placed on the grate of a reverberatory furnace. A tube of Heated i„ a 

 safety was fitted to the beak of the retort, which com muni- stone «*<«*• 

 cated with ajar filled with mercury. The who e being thus 

 arranged, a gentle heat was applied. This first degree of 

 heat sometimes occasioned the combustion of a small por- 

 tion of phosphorus ; but this may be prevented by cover- 

 ing the mixture with a little powdered potash. It is easy 

 to conceive, that this combustion is owing to the air con- 

 tained in the retort; and that, when the caloric has occa- 

 sioned a vacuum in the apparatus, no combustion can take 

 place. Of this we satisfied ourselves by a direct experi- 

 ment. We afterward increased the the, till the retort was of 

 a white heat. 



During the whole course of the process, a gas was Gas evolved, 

 evolved, the properties of which we shall mention pre- 

 sently. 



When the retort was completely cold, we broke it, and Residuum, 

 fouud in it a black ma^s. Its inside was entirely covered 

 with a coat shining as if metallic, and having the appear- 

 ance of carburet of iron. 



The black matter has a slightly alkaline taste, and was its properties* 

 but little soluble in cold water. By means of boiling how- 

 ever we dissolved it all, except a black powder, which was 

 precipitated. Boiling nitric acid likewise dissolves it; and 

 a black matter, which is nothing but oxide of carbon, sepa- 

 rates in a similar way. 



Neither of these solutions contains any thing but phos- 

 phate of potash. 



Among the various experiments we made there was one, Residuum n»t 

 in which we obtained a similar black mass, but without any Valine. 

 perceptible taste. Water had no action on it. Nitric acid 

 dissolved it, and separated from it oxide of carbon. The 

 portion of the tube communicating with the retort was 

 lined with a grayish substance, which took fire on coming 

 into colli-..- rt with water. As to the salt that remaned in 

 tiie retort, it was nothing but neutral phosphate of potash, 

 which we know to be nearly insoluble in water. 



In the course of these experiments we employed alter- Soda pave the 

 nately potash and soda, and instead of a stone retort, a re- Sdnic rc - nllts - 

 tort and tube of porcelain. The results were the same. 



The 



