1820.] Scientific Intelligence. 229 



the principal difference of opinion exists. I consider it as com- 

 posed of 



Phosphorus 100 



Oxygen QQ^ 



Berzelius, as composed of 



Phosphorus lOO'OO 



Oxygen 74-94 



Berzelius ascertained the composition of phosphorous acid in 

 the following manner : He dissolved 2*211 parts of protochloride 

 of phosphorus in water. Now it is known that when this com- 

 pound comes in contact with water, its two constituents ar& 

 ■converted respectively into muriatic acid and phosphorous acid 

 at the expense of a portion of the water, the chlorine uniting 

 with the hydrogen of that liquid ; while the phosphorus unites 

 with its oxygen. He threw down the muriatic acid by means of 

 nitrate of silver. The fused chloride of silver weighed 6"915. 

 Now the chlorine in this portion of chloride of silver amounts to 

 1'705. This weight of chlorine to become muriatic acid must- 

 combine with 0".0474 hydrogen. This hydrogen it acquired by 

 the decomposition of water, and this hydrogen must have been 

 in combination with eight times its weight of oxygen, or 0-3792, 

 which must be the quantity of oxygen that combined with the 

 phosphorus in 2-211 parts of protochloride of phosphorus. But 

 the phosphorus in the chloride was 2*211 — 1-705 = 0-506 ; so 

 that, according to this experiment, phosphorous acid is com- 

 posed of 



Phosphorus 506-0 or 100-00 



Oxygen 379-2 74-94 



But the consequences deduced from this experiment depend 

 upon assumptions which have not yet been demonstrated. If 

 the protochloride of phosphorus, have the property of absorbing 

 more chlorine than an atom, which seems to be the case, if the 

 analysis of it by Davy be nearly accurate, tlien the whole conclu- 

 sions deduced by Berzelius from the experiment, as far as the 

 constitution of phosphorous acid goes, fall to the ground. Now 

 Davy found protochloride of phosphorus a compound of 



Phosphorus 2-98 or 1-500 



Chlorine 10-G2 5-345 



Here the proportion of chlorine is almost one-fifth greater than 

 an atom. 



But let us consider protochloride of phosphorus as a compound 

 of one atom chlorine and one atom phosphorus. Its constituenta- 

 naust then be : 



Chlorine 4-5 



Phosphorus 1-5 



