230 



Intelligence and Miscellaneous Articles. 



composed under circumstances of interrupted attention, a few errors 

 have crept into the text, towards which I must request the reader's 

 indulgence. In that section I have endeavoured to extract, from a 

 mass of conflicting testimony, the most probable evidence of the two 

 generally admitted species of phosphureted hydrogen gas, consider- 

 ing the third variety as of too doubtful existence to be reasoned upon 

 as a definite compound. The experiments of Dumas, of which I have 

 given an account, have been recently repeated by M. Bufl', in the 

 laboratory of M. Gay Lussac. So far as respects proto-phosphureted 

 hydrogen, the results of Dumas were fully confirmed, especially that 

 100 volumes require 200 of oxygen gas for saturation. But in the 

 combustion of per-phosphureted hydrogen with oxygen, some differ- 

 ences were observed. This gas (containing from 13-.5 to 14-5 per 

 cent of impurity), when heated in a graduated glass vessel, deposited 

 phospiiorus without any change of volume, and, though it lost its 

 spontaneous inflammability, continued to be absorbable to the same 

 amount by solution of sulphate of copper. Besides being decomposed 

 by keeping, its composition appeared to be varied by the degree of 

 heat used in its production, so that we can never be sure of having 

 it twice alike. Heated in contact with copper, each volume expanded 

 to 1-5; mixed with three volumes of carbonic acid it burned com- 

 pletely both with oxygen gas and with air, without leaving any trace 

 of phosphorus. In the quantities of oxygen consumed by the com- 

 bustion of a given volume, great and unaccountable variations were 

 observed, the lowest being 204, and the highest 2/0 volumes of 

 oxygen, to 100 of the per-phosphureted gas. 



" Both gases agree in giving 1-.5 volume of hydrogen from each vo- 

 hime, when decomposed by antimony, zinc, potassium, or bi-chloride 

 ot mercury ; as well as in being absorbable by sulphuric acid, sulphate 

 of copper, and chloride of lime. — The following Table, which 1 have 

 compiled from various authorities, exhibits the two species in contrast 

 with each other. 



" Table (if the Gaseous Compounds of Hydrogen and Phosphorus. 



" The following Tables are added for the better comparison of the 

 composition of the phosphoric and phosphorous acids, as deducible 

 from the two proportions of oxygen, with which each variety of phos- 

 phureted hydrogen unites. 



" Hcsulls 



