328 



Phospohjus 

 analogous to 

 sulphur. 



Acted on by 

 the pile, 



«vo!ved pb«s- 

 phuretted hi- 

 drogen, 



potassium heat- 

 ed in phos- 

 phuretted hi- 

 drogen. 



ANALYTICAL .EXPERIMENTS ON PHOSPHORUS. 



quantity of sulphur evolved from them in this case when 

 perfectly dry and out of the contact of air, as I found in 

 an experiment on the sulphuret of copper and iron, exists 

 in its common state, and acts upon potassium, and is 

 affected by electricity, in the same manner as native sul- 

 phur, 



4. Analytical Experiments on Phosphorus. 



The same analogies apply to phosphorus as to sulphur, 

 and I have made a similar series of experiments on this in, 

 flammable substance. 



Common electrical sparks, passed through phosphorus, 

 did not evolve from it any permanent gas ; but when it was 

 acted upon by the voltaic electricity of the battery of five 

 hundred plates in the same manner as sulphur, gas was pro, 

 duced in considerable quantities, and the phosphorus became 

 of a deep red brown colour, like phosphorus that has been 

 inflamed and extinguished under water. The gas examined 

 proved to be phosphurctted hidrogen, and in one experU 

 inent, continued for some hours, a quantity estimated to be 

 nearly equal to four times the volume of the phosphorus 

 employed was given off. The light of the voltaic spark in 

 the phosphorus was at first a brilliant yellow, but as the 

 colour of the phosphorus changed, it appeared orange, 



I heated three grains of potassium in sixteen cubical inches 

 of phosphurctted hidrogen; as soon as it was fused, the 

 retort became filled with white fumes, and a reddish sub- 

 stance precipitated upon the sides and upper part of it. 

 The heat was applied for some minutes. No inflammation 

 took place*. When the retort was cool, the absorption 

 was found to be less than a cubical inch. The potassium 

 externally was of a deep brown colour, internally it was of 

 a dull lead colour. The residual gas had lost its property 

 of spoutaneous inflammation, but seemed still to contain a 

 small quantity of phosphorus in solution. 



* It ij stated, in the account before referred to of M. M. Gay- 

 Lussac and Thenard's experiments, that potassium inflames in 

 phosphuretted hidrogen. My experiments upon this gas have been 

 often repeated. I have never perceived any luminous appearance ; 

 bit I have always operated in daylight. 



6 Th« 



