40 DEPORT — 1884. 



to be preferred to the other name in vogne at that time — viz., ' liqueur 

 alkaline saturee de la matiere colorante du bleu de Prusse.' 



2. The name should be as far as possible in real correspondence with 

 the object. As corollaries to this rule he lays down that where a name is 

 made up of an adjective and a substantive the more essential and unalter- 

 able constituent should bear the substantive form ; also that the names of 

 discoverers, since they stand in no essential connection Avith the bodies 

 they discover, should find no place in the system. 



3. If the constitution of a body is unknown, it is better to give it a 

 name which conveys no meaning, than one which conveys a wrong one. 

 Hence he prefers to call the body of unknown composition which we now 

 know as potassium ferrocyanide, ' alkali Prussien,' rather than ' alkali 

 phlogistique.' 



4. In the choice of new names it is advisable to derive them from 

 roots in the best-known dead languages. 



5. Names must be adapted to the structure and natm*e of the different 

 languages in which they are to be used. 



De Morveau applies these principles to the nomenclature of 474 sub- 

 stances, belonging to the four classes, earths, alkalies, acids, and metals, 

 and the products of their union. In the naming of salts he forms words 

 for all the acids known to him, on the analogy of the terms vitriol and 

 nitre introduced by Macquer, so that the salts BaSo.„ CaCl 2 , acetate of 

 iron, are called respectively vitriol barotique, muriate calcaire, and acete- 

 martial. He also tries to fix one name for carbonic acid gas, and calls it 

 acide mephitique, and its salts muphites. The principal advance which we 

 find in De Morveau is, then, that acids receive names with uniform 

 terminations, and salts receive names indicating their being compositions 

 from acid and base. 



In 1787 Lavoisier and De Morveau, 1 with the assistance of Berthollet 

 and Fourcroy, prepared and laid before the French Academy a scheme of 

 chemical nomenclature based on the dualistic hypothesis, and their 

 proposals form the basis of the nomenclature still in use. A system of 

 nomenclature is necessarily bound up with a classification of known 

 substances, and so we find that Morveau and Lavoisier give a table of all 

 the substances to which they assign definite names arranged according tc- 

 their relationships one with another. The elements retain their ac- 

 customed names, except that the names oxygen, hydrogen, and azote are 

 introduced. The term oxide is introduced for the first time, and oxides 

 are looked on as substances in a state intermediate between the element 

 and its acid. Thus tney call the two oxides of arsenic oxide d'arsenic 

 (white arsenic) and acid arsenique ; and the two known oxides of 

 molybdenum, oxide de molybdene and acide molybdique. The corre- 

 spondence of the terminations '-ate ' and '-ic,' '-ite ' and '-OU3 ' in acids and 

 salts is introduced for the first time. The nomenclature of salts thus 

 came to be nearly identical with that now used. In this classification the 

 French chemists do not distinguish by generic names between higher and 

 lower basic oxides. 



The views thus developed by Lavoisier and Morveau found acceptance 

 all over Europe. Girrtanner translated the French names into German, 

 and several English chemists, such as Dickson and Kirwan, Chevenix and 

 Thomson, 2 adopted the system in its main outlines. Additions w r ere made 



1 Gom.pt. Bend., translated by George Pearson, M.D. 1794 ; 2nd ed. 1793. 

 • System of Chemistry, ed. 1802. 



