470 

 Table IV 



Me8srs. Playfair and Joule oti 



Showing the volumes occupied by certain Phosphates, 

 Arseniates, Carbonate of Soda and Cane-sugar. 



Designation. 



Volume in solution. 



Volume of salt. 



Name. 



Formula. 



S V 



feS 



■s o 



u 



Carbonate of soda 



Phosphate of soda 



Sub- phosphate"! 

 of soda J 



Arseniate of soda 



Sub-arseniate \ 



of soda J 



Cane-sugar 



NaO,CO2 + 10HO 

 r 2NaO, HO, PO5 1 

 I +24HO ]■ 



3NaO, P06-I-24HO 



rHO,2NaO,AsOs'l 

 t +24HO J 



3NaO, ASO5+24HO 



C12H11OH 



1434 

 359- J 



381-6j 



402-9 



425-2 

 171-61 



90 

 216-4 



216-8 



217-6 



215-6 

 99-5 



10 

 24 



24 



24 



24 

 11 



90 

 216 



216 



216 



216 

 99 



98-6 

 235-5 



235-2 



232-0 24 



235-6 24 



107-5 11 



98-0 

 236-2 



235-2 



235-2 



235-2 

 107-8 



1-463 

 1-627 



1-622 



1-713 



1-808 

 1-691 



1-454 

 1-525 



1-622 



1-736 



1-804 

 1-596 



Connected with the latter group, there is a class of salts 

 which come out uniformly with themselves, but the divisor of 

 which is not 1 1 in the solid state. We subjoin them in the 

 following group. 



Sulphate of Magnesia^ MgO, SO3 + 7H0 = 123-86.— 

 When this salt is dissolved in a large quantity of cold water, 

 the volume observed after solution is always less at ordinary 

 temperatures than that due to the water contained in the salt. 

 That this diminution is due to a contraction caused by an af- 

 finity of the salt for water is shown b}' the fact, that anhydrous 

 sulphate of magnesia dissolved in a large quantity of water 

 actually lessens, instead of increasing the bulk of the water; 

 and to compensate for this contraction, a certain tempera- 

 ture has to be given to the water. In the following expe- 

 riments with the sulphates of magnesia, zinc and iron, this 

 circumstance has been attended to, and the temperature is 

 given at which the results come out exact. 



31 grains of crystallized sulphate of magnesia were dissolved 

 in 3140 grains of water at 32°, and caused an increase of 

 15'22 ; at 85° the increase was 15'75. , . „ 



MgO, SO3 + 7HO, vol. in solution 63. .// i[&e 



Half an equivalent, 61*93 grains, being placed in a"sa{"u- 

 rated solution of the salt, caused an increase of 37"5 in one 

 experiment, but in three other experiments the increase was 

 not greater than 37'2 ; the temperature in all the cases being 



54°. 



