System of Chemistry, by Prof. Berzelius. 67 



English) is to be applied lo the electronegative ingredient. As, 

 agreeably to the prevailing nomenclature, which in this respect the 

 great Swedish chemist has not deemed it expedient to change, the 

 electropositive compounds of oxygen with radicals, forming electro- 

 positive bases, have each a termination in ide, it seems that consisten- 

 cy requires us, conformably with the English practice, to designate in 

 like manner analogous electropositive compounds of the electronega- 

 tive elements called by him " halogene.^^ But especially it would be 

 inconsistent not to put the same mark upon the compounds of sub- 

 stances which from their analogy with oxygen are placed in the same 

 " amphigenc " class. If there were insuperable reasons for retaining 

 the term oxide, as a generic name for the electropositive compounds 

 of oxygen, it seems to me inexpedient not to employ the words sul- 

 phide, selenide, and telluride, to designate the electropositive com- 

 pounds of sulphur, selenium, and tellurium. And since the three last 

 mentioned elements when united with hydrogen, form electronega- 

 tive compounds which act as acids, why not treat them as such, under 

 appellations corresponding with those heretofore used for that pur- 

 pose ? 



I conceive the following definitions to be justified by the practice 

 of modern chemists in general, as established in the case of oxacids 

 and oxibases. When two compounds capable of combining with 

 each other to form a tertium quid, have an ingredient common to both^ 

 and one of the compounds prefers the positive, the other the negative 

 pole of the voltaic series, we must deem the former an acid, the latter 

 a base. And again, all compounds having a sour taste, or which red- 

 den litmus, should be deemed acids in obedience to usage. 



I should think it preferable, if in adopting these definitions, the ter- 

 mination in ide was considered as applicable to all compounds of 

 electronegative principles with other substances, whether producing 

 electronegative or electropositive combinations, and that the terms 

 acid, and base, should be considered as severally indicating the sub- 

 ordinate electronegative, and electropositive compounds. In that 

 case oxybase, chloribase, fluobase, bromibase, iodobase, cyanobase, 

 sulphobase, telluribase, selenibase, would stand in opposition to oxa- 

 cid, chloracid, fluacid, bromacid, iodacid, cyanacid, sulphacid, selen- 

 acid, telluracid ; yet for convenience, the generic termination ide 

 might be used without any misunderstanding ; and so far, the prevail- 

 ing practice might remain unchanged. Resort to either appellation 

 would not, agreeably to custom, be necessary in speaking of salts or 



