70 System of Chemistry, by Prof. Berzelius. 



had precedency in all, as it lias in some cases. The word hydroflu- 

 oric does not harmonize with fluoboric, fluosilicic, fluochromic, fluo- 

 raolybdic, &;c. Fluorine being, in each compound, the electronega- 

 tive principle, the syllables indicating its presence, should in each 

 name occupy the same station. These remarks will apply, in the 

 case of acids formed with hydrogen, by all principles which are more 

 electronegative. Hence we should use the terms chlorohydric, fluo- 

 hydric, bromohydric, iodohydric, cyanhydric, instead of hydrochloric, 

 hydrofluoric, hydrobromic, hydriodic, hydrocyanic. 



These opinions, conceived last summer, were published by me in 

 the Journal of Pharmacy for October last. Since then, I find that in 

 the late edition of hisTraite, Thenard has actually employed the ap- 

 pellations above recommended. 



As by the British chemists the objectionable words have not been 

 definitively adopted ; the appellations muriatic and prussic, being still 

 much employed, it may not be inconvenient to them, to introduce 

 those which are recommended by consistency. In accordance with 

 the premises, the acids formed with hydrogen by sulphur, selenium, 

 and tellurium, would be called severally sulphydric, selenhydric, and 

 telluhydric acid. Compounds formed by the union of the acids thus 

 designated, with the bases severally generated by the same electro- 

 negative principles, would be called sulphydrates, selenhydrates, and 

 lelluhydrates, which are the names given to these compounds in the 

 Berzelian nomenclature. Influenced by the analogy, a student would 

 expect the electronegative ingredient of a sulphydrate to be sulphy- 

 dric acid, not a sulphide. The terminating syllable of this word, by 

 its associations, can only convey the conception of an electropositive 

 compound. 



By adhering to the plan of designating each acid by its most elec- 

 tronegative ingredient, the compounds of hydrogen and silicon, or of 

 hydrogen and boron with fluorine, would appear in a much more con- 

 sistent dress. In the compound named hydrofluoboric acid, and that 

 named hydrofluosilicic acid by Berzelius, fluorine is represented as 

 acting as a radical with hydrogen, while with boron and silicon it acts 

 as the electronegative principle. It has been shown that hydrogen, 

 no less than boron and silicon, must be considered as a combustible, 

 and of course a radical. This being admitted, if the compounds in 

 question are really entitled to be considered as distinct acids, their 

 names should respectively be fluohydroboric, or fluohydrosilicic acid. 

 But as I have elsewhere observed an incapacity to combine with ba- 



