194 Prof. Graham on the Diffusion of Liquids. 



metrical method of analysis followed is not so properly appli- 

 cable to these two acids as it is to all the others. 



3. Diffusion of Ammoniated Salts of Copper. 



It was interesting to compare together such related salts as 

 sulphate of copper, the ammoniated sulphate of copper or 

 soluble compound of sulphate of copper with 2 equivs. of am- 

 monia and the sulphate of ammonia. It is well known that 

 metallic oxides, or subsalts of metallic oxides, when dissolved 

 in ammonia or the fixed alkalies, are easily taken down by 

 animal charcoal. This does not happen with the ordinary 

 neutral salts of the same acids, which are held in solution by 

 a strong attraction. Supposing the existence of a scale of the 

 solvent attraction of water, the preponderance of the charcoal 

 attraction will mark a term in that scale. And if the solvent 

 force is nothing more than the diffusive tendency, it will follow 

 that salts which can be taken down by charcoal must be less 

 diffusible than those which cannot. 



Of sulphate of ammonia and sulphate of copper, solutions 

 were prepared, consisting of 4 anhydrous salt to 100 water, 

 the sulphate of ammonia being of course taken as NH 4 0, SO 3 . 

 The solution of the copper salt was divided into two portions, 

 one of which had caustic ammonia added to it in slight excess, 

 so as to produce the azure blue solution of ammonio-sulphate 

 of copper. 



The solutions were diffused for eight days, at a mean tem- 

 perature of 64°*9 for the sulphates and nitrates, and 67 0, 7 for 

 the chlorides. 



Table VI. — Diffusion of solutions, 4 salt to 100 water. 



Name of salt. 



Density of solution 



at temperature of 



experiment. 



. Anhydrous salt 

 diffused in grains. 



Sulphate of ammonia 



10235 

 1-0235 

 1-0369 

 1-0369 

 1-0308 

 1-0308 

 10136 

 1-0136 

 10323 

 1-0323 

 1-0228 

 1-0228 

 10100 

 1-0100 

 10328 

 1-0328 

 10209 

 1-0209 



1213 



11-96 



619 



6-51 



1-45 



1-43 



1615 



15-44 



9-77 



' 977 



177 



1-36 



16-18 



1700 



10-83 



10-48 



4-54 



3-94 



Sulphate of ammonia 



Sulphate of copper 



Sulphate of copper 



Ammonio-sulphate of copper 



Ammonio-sulphate of copper 



Nitrate of ammonia 



Nitrate of ammonia 





Nitrate of copper 



Ammonio-nitrate of copper 



Ammonio-nitrate of copper 



Chloride of ammonium 



Chloride of ammonium 



Chloride of copper 



Chloride of copper 



Ammonio-chloride of copper 



Ammonio-chloride of copper 



