376 
ON THE SOLUBILITY OF METALLIC OXIDES, 
II .—Protoxide of Copper. 
Citrate of Ammonia. 
Citrate of 
Soda. 
A lnmonia 
Dark-blue colour . 
Dark-blue 
colour. 
» 
55 
No change 
Brown 
precipitate 
Reddish- 
brown ppt. 
Carbonate of ammonia ... 
Potassa . 
Carbonate of potassa . 
Sulphide of ammonium ... 
Ferrocyanide of potassium 
5) 
}> 
Brown precipitate. 
Reddish-brown precipitate 
Citrate of Potasli. 
Dark-blue colour. 
55 
55 
No change. 
Brown precipitate 
No change. 
III .—Protoxide of Lead. 
Citrate of Ammonia. 
Citrate of 
Soda. 
Citrate of Potash. 
Ammonia . 
No change. 
As before 
As before. 
Carbonate of ammonia ... 
55 
55 
55 
Potassa . 
j» 
55 
55 
Carbonate of potassa. 
5) 
, » 
White precipi- 
tate. 
Hydrochloric acid . 
Ppt. (Pb Cl) . 
?> 
Sulphuric acid . 
Ppt. (PbO,SO,) . 
55 
» 
Citric acid . 
No change. 
Iodide of potassium . 
55 
55 
55 
55 
55 
Sulphide of ammonium... 
Ppt. (PbS) . 
55 
55 
Bichromate of potash. 
Yellow precipitate . 
Phosphate of soda . 
Milkiness . 
55 
55 
IV .—Peroxide of Bismuth. 
Citrate of Ammonia. 
Citrate of 
Soda. 
Citrate of Potash. 
Nitric acid . 
No change. 
As before 
Precipitate: Re¬ 
dissolving. 
Hydrochloric acid . 
n 
Precipitate. 
Sulphuric acid. 
55 
55 
Cloudiness. 
Acetic acid . 
55 
5> 
No change. 
Citric acid . 
» 
5» 
55 
Ammonia . 
55 
55 
55 
Carbonate of ammonia ... 
55 
55 
55 
Potassa . 
55 
V 
55 
Carbonate of potassa. 
55 
55 
55 
Bichromate of potash. 
55 
55 
55 
Phosphate of soda . 
55 
55 
55 
Iodide of potassium . 
55 
55 
5* 
Sulphide of ammonium ... 
Ppt. (BiS 3 ) . 
» 
Ppt. (Bi S 3 ) 
A knowledge of this solvent action of the alkaline citrates may he useful in two ways: 
firstly, as cautioning against the employment of metallic vessels in the preparation of 
the medicinal citrates ; and secondly, inasmuch as it may lead to improved methods of 
