£01 On definite Pfoporliuni. 



acid was precipitated by boiled water, and thr precipitate 

 veil washed with boiling water; it was pressed on a filter, 

 lasiily dried on a hut brick, put into a small glass retort, 

 and melted hv a red heal. Of this fused substance six 

 grammes were dis>()lved in pure nitric acid, and |)rccipitaied 

 'tviih nitrate of silver. The precipitate weighed, atter fu- 

 s-ion, 7' 12 gr., which implies (he presence ol' 1-321 gr. of 

 muriatic acid. This muriate consists therefore of 



Muriatic acid 26-42 Unro 



Protoxide of copper 7i5"5b 27t5'4 



Hence the quaunty of the protoxide which saturates 100 

 parts of muriatic acid contains 3093 of oxygen j for 

 il2-5 : ]2-o = 278-4: 30-93. 



B. Muriate of the Oxide of Copper. 



Four grammes of black oxide of copper were dissolved 

 in muriatic acid, and carefully dried, so as to drive off the 

 superfluous acid. Hence was obtained a bright liver-co- 

 loured mass, which recovered, when exposed to the air, iis 

 watei- of crystallization, and its colour, [becoming green as 

 at first, Kem. H. 331. Engl. Tr.] The salt was dissolved 

 in water, and precipitated with nitrate of silver. The mu- 

 riate, thus formed, weighed, when fused, 14-4 gr., an- 

 swering to 2-69 of muriatic acid. We have therefore for 

 the muriate of the oxide of copper. 



Muriatic acid 40-21 100-0 



Oxide 59-79 148-7 



Tf we calculate 'he result of this experiment from the 

 analyses of the sulphate of baryta, of the sulphate of copper, 

 consisting of lOO acid and lors oxide, and of the nuu'iate 

 of baryta, we obtain 194: 101-S = 288-4: 131-3, that is, 

 26 more of the oxide than the experiment exhibits. 



In this experiment 100 parts of muriatic acid require 30 

 of ox\c;en in the base by which they are saturated; for 

 125 : 2.')= 14S 7 : 29-74, or according to the last calcula- 

 tion, 30-26, which differs but little from 30-93, the result 

 •if the former experiment. I consider therefore this ex- 

 periment as an avlditional proof, that the oxide of copper 

 contains twice as much oxygen as the protoxide. And 

 that the protoxide of copper, which saturates a given quan- 

 tity o-f the muriatic acid, must contain the same quantity 

 of uxvgen as the oxide which is capable of saturating it, is 

 j)liced beyond all doubt by the mode of preparation of the 

 salt of the protoxide. 



C. Sulmtiriafe of Copper. 



A solution of the neutral muriate of copper \\;^s precipi- 

 tated 



