174 Gerhard fs Organic Chemistry. 



The terminations in ate and uret are restricted to saline com- 

 binations; the hydrocarbons have their ending in ene; the oxy- 

 genized volatile liquids, like the alcohols and essential oils, in ol; 

 and the alkaloids in ine. 



The second part of the work is devoted to a consideration of 

 the characters of the several classes of organic substances. The 

 salts as among the most important compounds are first noticed; 

 under this title are included the acids (salts of hydrogen) with 

 their derivations, the coupled acids and the various sesquisalts 

 and emetics. An acid may be characterized as a compound 

 which can exchange one or more equivalents of its hydrogen 

 for a metal, and which unites with alcohol to form an ether, 

 with the separation of the elements of water. We know at 

 present those which are capable of exchanging one, two or three 

 equivalents of their hydrogen, constituting monobasic, bibasic, 

 and tribasic salts. The terms bibasic and tribasic are often 

 applied to the compounds of neutral monobasic salts with certain 

 metallic oxyds ; the acetate of lead unites with two equivalents 

 of oxyd of lead to form the salts known as the tribasic acetate; 



in this but one equivalent of hydrogen is replaced by the metal 

 and the two equivalents of oxyd are but feebly united, perform- 

 ing perhaps a function analogous to water of crystallization. 

 Such as these M. Gerhardt conveniently distinguishes as surbasic 

 salts ; and the compound just noticed, which is G a (H 3 Pb)0* 

 -f Pb 2 O, will then be the bisurbasic acetate. 



The action of the oxyds of the formula M 2 O with acids re- 

 sults in the formation of neutral salts, and the elimination of the 

 elements of water, which is formed from the union of the oxygen 

 of the oxyd with the hydrogen of two equivalents of the acid. 

 The oxyds of the form M 4 3 , as the sesquioxyd of iron, unite 

 in the same manner with the separation of the elements of water, 

 but their three equivalents of oxygen form water with the re- 

 placeable hydrogen of six equivalents of the acid, and the residue 

 which replaces this is equal to only four equivalents. Thus 



6C 2 H 4 2 +Fe 4 0,=3H 2 0+C l2 H 18 Fe 4 12 . If we would 

 represent this substitution as equivalent, Fe* designated as 



Fe =H, then the peracetate of iron is C, H 3 Fe 2 . , 



In the same manner the sesquioxyd of 2 antimony Sb 2 3 ana 

 arsenious acid As 2 3 unite with the bibasic acids and form com- 

 pounds in which Sb 3 is substituted for H 6 or Sb, represented by 



our author as Sb a =H. Tartar emetic is an instance of tb« 

 class of compounds ; when the acid, tartrate of potash, is boitf 

 with sesquioxyd of antimony it dissolves, and on cooling, a ®\ 

 separates, which is C 4 H 4 KSb O, Aq. It is formed W»J 

 2C 4 H 5 K0 6 +Sb 2 3 = 2C 4 H 4 KSb0 7 +H 3 0. The «*y° 



