100 On the Definite Proportions in which the [Feb. 



matic matter with which it is usually impregnated, in the following 

 manner. I sublimed it in a moderate heat, the product of the sub- 

 limation is succinic acid, contaminated with colourless oil of amber, 

 which becomes coloured by exposure to the air. 1 combined it with 

 carbonate of ammonia, adding a slight excess of the alkali. I 

 then digested it with charcoal, prepared by exposing coagulated 

 blood to a strong heat in a covered crucible. This charcoal ab- 

 sorbed the empyreumatic matters, and allowed the succinate of am- 

 monia to crystallize of a white colour. From this succinate of 

 ammonia, I prepared by the addition of nitrate of lead, with the 

 precautions already stated, pure succinate of lead. 100 parts of 

 this succinate analysed by combustion gave 69*1 of oxide of lead. 

 Hence the salt is composed of 



Succinic acid 30-9 lOO'OO 



Oxide of Lead 69-1 223-62 



100-0 



But 223-62 of oxide of lead contain 16 of oxygen. 

 Subsuccinate of lead obtained by digesting the neutral succinate 

 in ammonia, dried in a vacuum at the temperature of boiling 

 water, and analyzed by combustion, yielded 86-93 per cent, of 

 oxide of lead. A great excess of ammonia poured upon this sub- 

 succinate did not alter it ; for it gave afterwards the same analytical 

 result. The subsuccinate of lead then is composed of 



Succinic acid 13-07 100 



Oxideof lead 86-93 666 



100-00 



But 223-64 X 3 = 670-8, which differs but little from 666. 

 Hence it is evident, that the succinic acid in this salt is combined 

 with three times as much base as in the neutral succinate. Of 

 course succinic acid must contain three volumes of oxygen. ^ 



1-294 of succinate of lead, equivalent to 0-4 of succinic acid, 

 produced by combustion 0-1536 of water, equivalent to 4-512 per 

 cent, of hydrogen, and 0-656 of carbonic acid in form of gas, to 

 which adding the 0-044 remaining in the soda, the whole amounts 

 to 0-7, equivalent to 47'6 per cent, of carbon. The acid therefore 

 is composed of 



Hydrogen 4-512 



Carbon 47-600 



Oxygen 47'888 



100-000 



But 16 X 8 = 48. Hence it follows, that the acid contalnt 

 three volumes of oxygen. We find that the carbon and hydrogen 

 amount each to four volumes; so that succinic acid is composed of 

 4 H -f 4 C + 3 O, which makes in a hundred parts 



