398 hitclligejice and Miscellaneous Articles, 



Another pectate of silver was procured by pouring the sohition of 

 pectate of ammonia into that of nitrate of silver. This was com. 

 posed of — 



Pectic acid 63*05 



Silver 36-93— 100- 



A second pectate of silver was formed by pouring a solution of 

 nitrate of silver into one of pectate of ammonia evaporated in vacuo ; 

 this solution was neutral to test papers. It was formed of — 



Pectic acid 59*612 



Oxide of silver 40-388— 100- 



A third pectate of silver, also procured from pectate of ammonia, 

 evaporated in vacuo, gave — 



Pectic acid 58*983 



Oxide of silver 41-017— 100' 



Lastly, nitrate of silver was added to solution of pectate of am- 

 monia in which the alkali was in excess ; as oxide of silver is soluble 

 in ammonia, it was hoped that neutral pectate would be precipi- 

 tated ; but this was not the case ; for the affinity of the ammonia 

 for the oxide of silver counterbalanced that of the pectic acid. 

 The results of two experiments were — 



Pectic acid 61-52 63-32 



Oxide of silver 38*48 36-68 



100- 100- 



All these analyses, the author concludes, indicate the same com- 

 position for pectic acid, but the capacity of saturation, he observes, 

 remains undetermined. 



[Taking, however, something near a mean of the results, and 

 comparing them with those of the direct analysis, it appears that 

 pectic acid is composed of — 



8 eq. of hydrogen 8 or 4'76 



12 carbon 72 42*85 



11 oxygen 88 52-39 



Equivalent 168 100- 



And supposing pectate of silver to be composed of one equivalent 

 of acid and base, it will consist of — 



1 eq. of pectic acid .... 168 or 59*15 

 1 oxide of silver ..116 40-85 



Equivalent 284 100- R.P.] 



Pectate of Lead was prepared by adding a solution of acetate of lead 

 to one of pectate of ammonia, which was slightly alkahne to test paper. 

 This precipitate was composed of — 



Pectic acid 51-256 



Oxide of lead 48-744—100- 



[This would give very nearly 168 pectic acid to 160 oxide of 

 lead. It appears, therefore, that the excess of ammonia precipi- 

 tated uncombined oxide of lead ; for a neutral pectate would consist 

 of 168 and 112 oxide ; if it had consisted of equal weights of acid 



