502 Scientific Proceedings, Royal Dublin Society. 
molecular heats of fusion and vaporization, and the molecular heat 
of solution, of formation in solution, and of neutralization ; and, 
for convenience in calculation, the total molecular heat of fusion 
and vaporization should also be tabulated, that is, the heat necessary 
to raise the substance from 15° C. to the temperature of fusion or 
vaporization and then fuse or vaporize it. Many of the physical 
data are wanting, but anything that clearly brings out what is 
wanting is one step in the direction of securing it. 
[ will now give some thermo-chemical Exercises in illustration 
of the proposed notation :— 
1. Given that 12 grams of carbon in the state of diamond (a) 
gives on combustion to carbon dioxide 94°3 kilogram degrees of 
heat. State this in the notation 
ECO, = 94:°3K°. 
2. Given the above, and the fact that the heat evolved on the 
solidification of 44 grams of carbonic acid is 5:8 kilogram degrees. 
Express in proper form the calculation for the heat of formation 
of carbonic acid in the solid state. 
ECO, = 94:3K°. 
& (CO) = 5-8K°. 
ECO, = 100-1K°. 
3. The heat of formation of a gram molecule of CS, in the 
liquid state is - 12°7K°, that of CO, is 94:3K°, and that of SO, is 
69:2K°: find the heat of combustion of C8,. 
Let E[CS.+ 60= CO, + 280,] = «K°. 
Then — EOS, - 6£0 + ECO, + 2ESO, = z. 
Therefore +127- O +943 +1884 = x. 
245°4 = a. 
4. Given the heat of formation of oxide of copper and nitric 
acid, and the heat of neutralization of nitric acid by the oxide: 
find the heat of formation of the salt in solution. 
