﻿464 Dr. E. J. Mills on Statical and 



The term salt was likewise concrete in its primitive significa- 

 tion, having been from time immemorial applied to culinary salt. 

 Aristotle denoted by it the evaporated lixivium of wood-ash ; 

 Dioscorides and Pliny seem to have called crude soda by this 

 same name, the latter naturalist using it generally for substances 

 which could be recovered from water by evaporation. Such per- 

 haps was the practice of Geber and certain alchemists of the 

 west. Basil Valentine classified the vitriols apart as metallic 

 salts ; and from his time the word salt had, as one of its mean- 

 ings, that of a constituent indestructible by ignition. This, ac- 

 cording to Paracelsus, may be found in all bodies ; moreover 

 alum and the vitriols are salts. Other chemists of the sixteenth 

 century understood by salts substances which in taste and solu- 

 bility resemble common salt. Palissy included sugar in the 

 list. In the seventeenth century Lemery defined a neutral salt 

 (sel sale) as an alkali charged with acid ; Van Helmont observed 

 that salts are composed of two opposite constituents ; Tachenius 

 stated that all salts are decomposable into acid and alkali. Ac- 

 cording to Becher, a salt contains elementary earth and water ; 

 according to Stahl, acids, alkalies, and salts are transmutable 

 inter se, and consist of the same ingredients. Newton called 

 water a salt. In the next century Boerhaave defined salts as 

 soluble in water, fusible, and sapid ; the vitriols he excepted, as 

 being semimetals. Bergmann and Kirwan depended especially 

 upon taste and solubility in a certain proportion of water. 



Rouelle (whose example was followed by Trommsdorf and La- 

 voisier) regarded a salt as a compound of an acid and a base. 

 But, as analytical knowledge advanced, it was found that the 

 definition required to be amended in order to include sodic chlo- 

 ride and its analogues ; and accordingly we find Berzelius, in the 

 year 1 825, arranging a new and matured classification of salts, and 

 specifying electrochemical indifference as the appropriate idea to be 

 connected with them, Gerhardt defined a salt as a binomial 

 {"corps binome"), prone to double decomposition; and Griffin 

 understood by it " a compound of two radicals/" 



The idea represented by the term Base is much older than the 

 word. Thus, in Lemery's conception of a salt, it is the alkali 

 which comes first, and is "cloyed or filled with acid/'' Stahl 

 also, referring to the substance which, in common salt, he sup- 

 posed to be united with hydric chloride, calls it "materia ilia 

 quse sali corpus preebet." Duhamel. Rouelle, and others in the 

 last century used the name base to express " that which gives a 

 concrete or solid form " to a salt. In this century it has been 

 chiefly used to signify an oxidized body, having properties com- 

 plementary to an acid ; at present it stands in a generic relation 

 to the word alkali. 



