262 Prof. Graham on the Diffusion of Liquids. 



afterwards, was ascertained by an alkalimetrical process, the 

 neutralization being effected at the boiling-point. The follow- 

 ing are the results : — 



Experiment I. Diffusion product"! 9*06 grs. of carbonate of 



into water J soda. 



Experiment II. Diffusion product! 8'82 grs. of carbonate of 



into solution of chloride of sodium J soda. 

 Experiment III. Diffusion product 1 9*10 grs. of carbonate of 



into solution of chloride of sodium J soda. 

 It thus appears that 4 per cent, of chloride of sodium 

 present in the water atmosphere of the jar has no sensible 

 effect in retarding the diffusion into it, from the solution cell, 

 of carbonate of soda from a solution containing also 4 per 

 cent, of the latter. 



(2.) The experiment was varied by allowing the solution 

 of carbonate of soda to diffuse into a solution of sulphate of 

 soda, a salt more similar to the former in solubility and com- 

 position. The solution of the latter, containing 4 per cent., 

 was of density 1*0352. The temperature and period of dif- 

 fusion were the same as before: — 



Experiment IV. Diffusion product! 7*84 grs. of carbonate of 



into solution of sulphate of soda J soda. 

 Experiment V. Diffusion product! 7*82 grs. of carbonate of 



into solution of sulphate of soda J soda. 



Here we find a small reduction in the quantity of carbonate 

 of soda diffused, amounting to one-eighth of the whole. The 

 sulphate of soda has therefore exercised a positive interference 

 in checking the diffusion of the carbonate to that extent. So 

 small and disproportionate an effect however is scarcely suffi- 

 cient to establish the existence of a mutual elasticity and re- 

 sistance between these two salts. 



Still it might be said, may not the diffusion of one salt be 

 resisted by another salt which is strictly isomorphous with the 

 first? 



(3.) A solution of 4 parts of nitrate of potash to 100 of 

 water, of density 1'0241, placed in the solution phial, was 

 allowed to communicate with water containing 4 per cent, of 

 nitrate of ammonia in the water-jar, which last solution was 

 of density 1*0136; with all other circumstances as before. 

 With one solution phial having the usual aperture, 1*175 inch, 

 the diffusion product was 15*32 grs. of nitrate of potash. With 

 a second phial, having a larger aperture of 1*190 inch, the 

 diffusion product was 18*03 grs. of nitrate of potash. No 

 comparative experiment, on the diffusion of nitrate of potash 

 into water, was made at the same time. But nitrate of am- 

 monia, which appeared before to coincide in diffusibility with 



