196 Prof. Graham on the Diffusion of Liquids, 



magnesia alone in water, as 1 salt to 10 water, compared with 

 sulphate of water, also as 1 to 10, the disparity in the diffusion 

 of these two salts was less considerable, being only as 1 to 

 2*385, instead of 1 to 3 or 4. 



(2.) A solution was also diffused of 1 part of anhydrous 

 sulphate of soda and 1 part of chloride of sodium in 10 parts 

 of water, for four days at 61°'5. The salt which diffused out 

 in that time consisted of — 



Sulphate of soda .... 9*48 grs. 

 Chloride of sodium . . . 17*80 grs. 



27*28 grs. 



The sulphate of soda in the last experiment had begun to 

 crystallize in the solution phial, from a slight fall of tempera- 

 ture, before the diffusion was interrupted, a circumstance 

 which may have contributed to increase the inequality of the 

 proportions diffused of these two salts. 



(3.) A solution of equal weights of anhydrous carbonate of 

 soda and chloride of sodium, namely, of 4 parts of the one 

 salt and 4 parts of the other, to 100 water, was diffused from 

 3 four-ounce phials of 1*25 inch aperture, at a mean tempe- 

 rature of 57°*9 and for seven days. The diffusion product 

 amounted to 17*10, 17*58 and 18*13 grs. of mixed salt in the 

 three experiments. The analysis of the last product of 18*13 

 grs. gave — 



Carbonate of soda . . . 5*68 31*33 



Chloride of sodium . . 12*45 68*67 



18*13 10000 



Here the carbonate of soda presents a diffusion less than 

 one-half of that of chloride of sodium. The difference is again 

 greater than the peculiar diffusibilities of the same salts as 

 they appear when the salts are separately diffused. For in 

 experiments made in the same phials with solutions of 4 parts 

 of each salt singly to 100 water, but with a lower temperature 

 by 3°*6, namely, at 54°*3, the diffusion product of the carbo- 

 nate of soda was 7*17 and 7*34 grs. in two experiments, of 

 which the mean is 7*25 grs. ; while the diffusion product of 

 the chloride of sodium was 11*18 and 10*73 grs. in two expe- 

 riments, of which the mean is 10*95 grs. The quantity of 

 chloride of sodium diffused being taken at 100 in both sets of 

 experiments, we have diffused — 



Of carbonate of soda 66*18, when diffused singly. 

 Of carbonate of soda 45*64, when diffused with chloride of 

 sodium. 



