478 Messrs. Play fair and Joule ortAVv. 



grains) being dissolved in 1000 grains of water, caused an in- 

 crease of 20*0 at 60° ; and a repetition of the experiment at the 

 same temperature gave the increase 20*1 . «^ fioeiyib arane 



I. Sulph. magnesia and ammonia, vol. in solution SO'O 

 II. ... , ^^ ... ... ... 80-4 



'^i'.^'L Mean . . 80'^;: 



The same quantity of salt placed in a saturated solution, 

 gave on two occasions a rise in thestem of 26'3 at a tempera- 

 ture of 60°. l3fdw <'.fio<r!«3T io! 'xoslvif:. 



I. II. Sulph, magnesia and ammonia, vol. of salt 105*2 . 1*721 

 Sulphate of Iron and Potash, FeO, SOg + KO, SO3 + 6HO 

 = 216'73. — The eighth of an equivalent (2709 grains), when 

 dissolved in 1000 of water, caused an increase of 9 at a tem- 

 perature of 65°. 



Sulph. iron and potash, vol. in solution 72. 



The same quantity immersed in a saturated solution occa- 

 sioned a rise in the stem in two experiments 12*3 at a tem- 

 perature of 61°. 



Sp. gr. 



I. II. Sulph. iron and potash, vol. of salt 98*4 ... 2*202 

 Sulphate of Iron and Ammonia, FeO, SO3 + NH4O SOg 



+ 6HO = 195'55. — On dissolving 33*45 grains of this salt in 

 1000 of water, the increase in the first experiment was 13*4", 

 in the second 14, both at a temperature of 59°; a third expe- 

 riment with 66*9 grains, gave the increase 28 at the same tem- 

 perature. 



I. Sulph. iron and ammonia, vol. in solution 

 II. 

 III. 



Mean . . 



48*89 grains of the salt being projected into a saturated so- 

 lution, caused in the first experiment an increase of 26*4, in 

 the second of 26*5. 



Sp. gr. 



I. Sulph. iron and ammonia, vol. of salt 105*6 ... 1*851 



II. ... ... ... 106*0 ... 1*845 



Mean . . 105*8 ... 1*848 

 In the last section we gave the volumes occupied by those 

 salts which did not occupy any space of themselves, but merely 

 that due to their combined water. The divisor for the vo- 

 lumes observed in solution was therefore necessarily 9, or the 

 atomic volume of water itself. But in this section we have 

 ..experimented upon salts which take up space quite inde- 



