ON CHEMICAL NOMENCLATURE. 43 



chemists oxy-, by others hyperoxyniuriate. Thomson also calls 

 mercuric nitrate, oxynitrate, and says that on adding hot water to it an 

 insoluble subnitrate and a soluble supernitrate are formed. 



1811.— In Klaproth and Wolff's ' Dictionary of Chemistry' (French 

 trans.), we find the names sulphate acide de potasse, sulphate de fer 

 oxidule (=FeS0 4 ) ; for the two potassium carbonates, the names carbonate 

 sature and nonsature. 



1811. — Berzelius l uses entirely distinct means of denoting the two 

 classes of salts with which we have been dealing. To mark the degree 

 of oxidation of the base of a salt, he adds the termination -ous, or -ic, 

 to the name of the metal — e.g. nitras mercurosus and nitras mercaricus., 

 To denote the degree of acidity or basicity of a salt, he prefixes super- 

 or sub-, to the name denoting the acid. From his language, it seems 

 as though he had invented this method independently. In the cases 

 where more than one acid or basic salt is found, he denotes the most acid 

 salt by the adjective supremus, and the most basic by infimus, e.g. — 



Superoxalas kalicus supremus. 

 Subnitras plumbicus infimus. 



1829. — In his later works — e.g. in the French edition of his Treatise, 

 1829 — ho makes a difference in the nomenclature between haloid and 

 amphid salts. In the case of acid haloids, he adds the word acid to the 

 name of the salt, e.g. — 



Fluorure potassique acide. 



Basic salts of this class are named thus : — 



Chlorure plombique bibasique. 



,, „ tribasique, &c. 



In the case of acid amphid salts, he drops the word acid ; but prefixes to 

 the name of the acid a suffix indicating the number of acid molecules, 

 e.g.— 



Bisulphate sodique. 



Zweif'ach phosphorsaures natron. 



Basic salts are named thus : — 



Sous-sulphate trialuminique. 



1827. — A somewhat similar system is adopted by Thenard. 2 He 

 introduces into the name of each salt the full name (according to 

 Thomson's system) of the oxide supposed to exist in it, thus: — 



Sous-sulphate de deutoxide de mercure. 



All these attempts at naming acid salts were founded on a false idea 

 of their composition, inasmuch as it was not known that hydrogen is a 

 constituent of bisulphate of potash. Thus in Turner's ' Chemistry ' we 

 find the formulas : — ■ 



Sulphate of potassa, KO + S0 3 . 

 Bisulphate „ KO + 2S0 3 . 



1 Journal de Physique, vol. lxxii. p. 26G. 



2 Traite, 5th ed. 1827. 



