984? 



hoi, as in water, with some singular exceptions, such as chloride of 

 mercury. 



Nitrate of Baryta, — The time of diffusion of this and the two fol- 

 lowing nitrates was ll'^S days*. The salt diffused was precipitated 

 by sulphuric acid, and calculated from the weight of the sulphate of 

 baryta formed. 



Diffusion of nitrate of baryta in 11-43 days at 64f°*l ; two cells : — 



Grs. Ratio. 



From 1 per cent, solution 7*72 1-026 



From 2 per cent, solution 15°04? 2 



From 4 per cent, solution 29*60 3"936 



From 8 per cent, solution , . . 54*50 7*247 



The diffusion of nitrate of strontia almost coincides with that of 

 the isomorphous nitrate of baryta at the same temperature. 

 Diffusion from 1 per cent, solutions at 51°*5 in 11*43 days: — 



Nitrate of baryta 6*73 100 



Nitrate of strontia 6*79 100-89 



Nitrate of Lime. — The diffusate was evaporated to dryness with 

 an excess of sulphuric acid, and the nitrate of lime, which is always 

 supposed anhydrous, was estimated from the sulphate of lime pro- 

 duced. 



Diffusion of nitrate of lime in 11*43 days at 64°*1 ; two cells: — 



Grs. Ratio. 



From 1 per cent, solution 7*66 1*021 



From 2 per cent, solution 15*01 2 



From 4 per cent, solution 29*04 3*872 



From 8 per cent, solution 55*10 7*334 



The results throughout for this salt are almost identical with those 

 of nitrate of baryta, although these two salts differ greatly in solu- 

 bility, and in one being a hydrated, and the other an anhydrous salt. 



Acetates of Lead and Baryta.- — Diffused for 16*166 days ; the 

 time chosen before for sulphate of magnesia, with seven days for 

 chloride of sodium. These salts were diffused into water slightly 

 acidulated with acetic acid. 



Diffusion of 1 per cent, solutions in 16*166 days; two cells: — 



Acetate of baryta at 53°-5 7*50 100 



Acetate of lead at 53°*1 7*84 104*53 



Here, of two isomorphous salts, that of greatest atomic weight 

 sensibly exceeds the other in diffusibility. 



Chlorides of Barium and Strontium. — The diffusion of these salts 

 being manifestly more rapid than that of the chloride of calcium, a 

 shorter time was tried, which is to seven days, the time of chloride 

 of sodium, as the square root of 3 to the square root of 4*5. 



* This time is to that of sulphate of magnesia (16-166 days) as the square root 

 of 8 is to the square root of 16 ; but does not appear to express the true relation 

 between these salts. 



