Dr. Andrews's Report on the Heat of Combination. 523 

 Chloride of Barium and Sulphate of Ammonia. 



O o 



Temperature or air 1 1'3 1 1'l 



Increments observed 1'85 1*84 



Heat for 1 grm. BaO, SO3 24<-2 24.*1 



Heat for 1 equiv. BaO, SO3 . , 352-1 



Nitrate of Barytes and Sulphate of Magnesia. — As 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. 



Temperature of air 13*9 li'^t 



Increments observed 0*82 0*82 



Heat for 1 grm. BaO, SO3 .... 22*2 21-2 



Heat for 1 equiv. BaO, SO3 . . 3I6'4 



Nitrate of Barytes and Sulphate of Soda. 



o 



Temperature of air , . 14.'4, 



Increment observed 0'75 



Heat for 1 grm. BaO, SO3 20*5 



Heat for 1 equiv. BaO, SO3 298'9 



Nitrate of Barytes and Sulphate of Zinc. 



o o 



Temperature of air 13*9 14i'l 



Increments observed 0*83 0*83 



Heat for 1 grm. BaO, SO3 22*0 22*0 



Heat for 1 equiv. BaO, SO3 . . 320*7 



Nitrate of Barytes and Sulphate of Copper. 



o o 



Temperature of air l^'^ 14'4< 



Increments observed 0"88 0*91 



Heat for 1 grm. BaO, SO3 .... 23*0 24-5 



Heat for 1 equiv. BaO, SO3 . . 346-2 



The salts of lead were next examined. The precipitation of the 

 sulphate of lead took place with the same facility as that of the sul- 

 phate of barytes, the thermometer attaining the maximum in eight 

 minutes. 



Acetate of Lead and Sulphate of Magnesia. — The acetate of lead 

 was pure and in crystals, 4*1 7 grms. precipitated byoxalate of ammonia 

 gave 2*454 grms. oxide of lead, which exactly agrees with the theo- 

 retical composition of the salt. In each of the following experi- 

 ments, 30"80 grms. acetate of lead were taken, corresponding to 24*63 

 sulphate of lead : — 



Temperature of air 12*7 12*3 



Increments observed I'Ol 0'97 



Heat for 1 grm. PbO, SO3 ^-9 9-9 



Heat for 1 equiv. PbO, SO3 .. 187-6 



2 M2 



