of the Elements. 



431 



The terhydrides and their representatives by substitution are 

 capable of uniting with oxygen in several proportions, vi^ith the 

 exception of the nitrogenized compounds. Thus we have, — 



H^P H^As 



Phosphamine. Arscnamine. 



CFPO ;HMe2AsO 



Phosphorus oxychloride. Hydrate of kakodyle 



HMe2 As02 



Kakodylic acid. 



H^AsO^ 



Arsenious acid. 



H^AsO" 



Arsenic acid. 



H^Sb 



Stibamine. 



Et3 SbO 



Oxide of stibethyle. 



Et3 SbO^ ? 



CFBi 



Tcrchloride of bismuth. 



Et^BiO 



Oxide of bismuthethyle . 



H3P02 



Hypophosphorous acid 



H3P03 H^AsO^ H^SbO^ H^BiO^ 



Phosphorous acid. Arsenious acid. Antimonious acid. Hydrate of bismuth. 



H3P04 H^AsO" H^SbO'* 



Phosphoric acid. Arsenic acid. Antimonic acid. 



There exists a series of chlorinated compounds the constitution 

 of which may be represented as resulting from a substitution of 

 two atoms of chlorine for one of oxygen in the protoxidized 

 compounds. 

 Oxychloride of phosphorus . PCPO 



Oxide of triethylphosphamine PEt^O 

 Oxychloride of antimony . . SbCPO 

 Oxide of triethylstibamine* . SbEt^O 



PCI' C12 or PCP Pentachloride of 

 phosphorus. 



PEt' C12 Chloride of triethylphos- 

 phamine. 



SbCP CP or SbCls Pentachloride 

 of antimony. 



SbEt-^ CI- Chloride of triethylstib- 

 amine. 



The oxides or anhydrides, and the sulphides of phosphorus, 

 arsenic, antimony and bismuth, manifest a general correspond- 

 ence both in properties and formulse. The correspondence rather 

 in formulse than in properties extends to the nitrogen compounds. 



The teroxides are the most important and the most uniform 

 in properties. The teroxides of nitrogen and phosphorus are 

 powerful anhydrous acids. The teroxide of arsenic is but a weak 

 acid, that of antimony being still weaker, while that of bismuth 

 is neutral or basic. These three last teroxides are all of them 

 capable of acting as bases; in which case they replace three atoms 

 of metallic protoxide ; or rather, an atom of each metal is capable 



* That Lcewig's formulae for the oxides and chlorides of stibethyle are 

 correct, is rendered more than ))robable by Ilofuiaiui's recent production of 

 analogous phosphorus compounds. 



