yb REPORT—1849. 
solution, floated in the larger, and could be rapidly rotated, so as to produce 
in a short time a perfect equilibrium of temperature throughout the whole 
apparatus. The thermometer attained a maximum about 8! after the solutions 
were mixed. I have elsewhere indicated the precautions to be taken in 
such experiments, and shall therefore not refer to them here. In the fol- 
lowing statements, I have given the temperature of the air, the increment 
actually observed in Centigrade degrees, and the number of degrees through 
which | grm. of water would be raised by the precipitation of 1 grm. and 
1 equiv. (oxygen=1) of the precipitate. In calculating the latter numbers, 
all the usual corrections were applied to the observed increments of tem- 
perature :— 5 5 
Temperature of air .......... 18°3 144 
‘Increments observed ........ 1:95 1:96 
Heat for 1 grm. BaO, SO,.... 25°4 25:2 
Heat for 1 equiv. BaO,SO, .. 368°9 
Chloride of Barium and Sulphate of Soda,—The same weight of chloride 
of barium taken as before, and an equivalent weight of sulphate of soda. 
° 
Temperature of air......... - 20:2 187 
Increments observed ........ 1°57 1°55 
Heat for 1 grm. BaO, SO, .... 20°4 20°1 
Heat for 1 equiv. BaO, SO, .. 2945 
Chloride of Barium and Sulphate of Zine. 
Temperature of air .......... 19°7 19:6 
Increments observed ........ 1°69 1°72 
Heat for 1 grm. BaO, SO,.... 22°2 22-4 
Heat for 1 equiv. BaO, SO, .. 325'1 
Chloride of Barium and Protosulphate of Iron. 
fo} 
Temperature of air.............. 18-8 
Increment observed............-- 1-99 
Heat for 1 grm. BaO, SO,........ 25°6 
Heat for 1 equiv. BaO, SO, ...... 373°2 
Chloride of Barium and Sulphate of Copper. 
Temperature of air.......... 175 176 
Increments observed ........ 1°85 1°85 
Heat for 1 grm. BaO, SO, .... 247 246 
Heat for 1 equiv. BaO, SO, .. 3594 
Chloride“of Barium and Sulphate of Ammonia. 
Temperature of air.......... 11-3 11 
Increments observed .......- 1°85 1°84 
Heat for 1 grm. BaO, SO, .... 242 241 
Heat for 1 equiv. BaO, SO, .. 352°1 
Nitrate of Barytes and Sulphate of Magnesia—aAs the nitrate of barytes 
is sparingly soluble in water, 10°6 grms. only were taken, which is equivalent 
to half the quantity of chloride of barium used in the foregoing experiments. 
The other salts were reduced in the same proportion, 
fe} 
Temperature of air.......... 13:9 144 
Increments observed ........ 0°82 0°82 
Heat for 1 grm. BaO, SO,.... 22:2 21°2 
Heat for 1 equiv. BaO, SO, .. 3164 

