192 Prof. Graham on the Diffusion of Liquids, 



Before adverting to the relations in diffusibility which ap- 

 pear to exist between certain salts in the preceding table, I 

 may state <he results of the diffusion of the same solutions at 

 a lower temperature. 



Table IV. — Diffusion of solutions of 10 salt to 100 water 

 at 37°'5. 



Name of salt. 



Anhydrous salt diffused. 



In grains. 



Means. 



Chloride of sodium 



22-21 



22-74 22-47 



22-53 



23-05 22-79 



31-14 31-14 



Chloride of sodium 



Nitrate of soda 



Nitrate of soda 



Chloride of ammonium 



Nitrate of potash 



28-84 





Nitrate of potash 



28-56 

 29-19 

 28-10 

 21-42 

 31*11 

 28-60 

 13-03 

 13-11 

 11-87 

 13-33 



28*70 

 29-19 

 28-10 



21-42 



29*85 

 13-07 

 12-60 



Nitrate of ammonia 



Iodide of potassium 



Chloride of barium 



Sulphate of water 



Sulphate of water 



Sulphate of magnesia 



Sulphate of magnesia 



Sulphate of zinc.... 



Sulphate of zinc 









The near equality of the quantities diffused of certain iso- 

 morphous salts is striking at both temperatures. Chloride of 

 potassium and chloride of ammonium give 40 o, 15 and 40 o, 20 

 grs. respectively in the first table. Nitrate of potash and ni- 

 trate of ammonia 3555 (mean) and 35°-3 grs. respectively in 

 the first table, and 28*70 and 29*19 grs. in the second table. 

 Sulphate of magnesia and sulphate of zinc 15*45 and 15*8 grs. 

 (means) in the first table, with 13*07 and 12 60 grs. in the 

 second. The relation observed is the more remarkable, that it 

 is that of equal weights of the salts diffused, and not of atomi- 

 cally equivalent weights. In the salts of ammonia and potash, 

 this equality of diffusion is exhibited also, notwithstanding con- 

 siderable differences in density between their solutions ; the 

 density of the solution of chloride of ammonium, for instance, 

 being 1*0280 and that of chloride of potassium 1*0596. It 

 may have some relation however, but not a simple one, to the 

 density of the solutions; sulphate of magnesia, of which the 

 solution is most dense, being most slowly diffusive; and salts 

 of soda being slower, as they are generally denser in solution, 

 than the corresponding salts of potash. Nor does it depend 



