14 W. G. Mixter — Thermal Constants of Acetylene. 



Experiment 2. — Acetylene, 6*4419 grams ; water and water 

 equivalent, 3482*2 grams. 



Minutes. Temperature. . Temperature interval. 



18-201 



1 18-203 



2 18-206 22-039 — 18-209 + 0--011 =3-841° 



3 18-209 



4 21-6 Heat observed, 3482-2X3-841 = 13375° 



5 22-0 



6 22*044 ' For 1 gram of acetylene 2076° 



7 22-042 



8 22-039 



9 22-036 



10 22-034 



11 22-031 



12 22-028 



Experiment 3. — Acetylene, 6*1254 grams; water and water 

 equivalent, 3484*9 grams. 



Minutes. Temperature. Temperature interval. 



18-333 



1 18-337 



2 18*340 21-982 -18-34 + 0*008 = 3*65° 



3 21*8 



4 21-9 Heat observed, 3484-9X3-65 = 12720° 



5 21*984 



6 21-984 For 1 gram of acetylene 2077° 



7 21*982 



8 21-980 



9 21-978 



10 21-976 



11 21*974 



The mean temperature in these experiments was 20-12°. 

 The average of the results, 2060, 2076 and 2077, is 2071 for the 

 heat of dissociation of one gram of acetylene at 20° and in terms 

 of the water calorie at this temperature. For the gram mole- 

 cule, 26*016, it is 53879. This figure is one per cent higher than 

 that found in the earlier experiments and carries a greater 

 weight on account of somewhat improved apparatus. 



Heat of Combustion of Acetylene. 



The acetylene used was made from carbide and collected over 

 water containing ferrous hydroxide to absorb oxygen. The 

 bomb was filled and the percentage of acetylene in the gas 

 determined as already described, and the usual precautions 

 were taken for finding the volume, temperature, and pressure 

 of the gas. The density of acetylene adopted, 0*0011687, was 

 derived from the molecular weight, 26*016, and the density of 



