tI8 Rcv.J.B.Emmetionthe {Ffetf. 



for heat ; and if we knew the ratios of the absolute quantity of 

 heat contained in bodies, we should be able to estimate the 

 real quo.ntity evolved during combustion and chemical changes ; 

 however as the heat evolved or absorbed depends primarily upon 

 capacity, the table furnishes approximations which probably do 

 not differ much from the truth, and leads to several important 

 conclusions. An example or two will show its application. 



Atomic capacity of carbon = 0*197 



+ capacity of two atoms of oxygen. . . = 9'500 



y-697 



— atomic capacity, carbonic acid 0'414 



.-. caloric evolved by the combustion of one 



atom of carbon , = 9'283 



Atomic capacity of hydrogen = 2*85 



+ atomic capacity of oxygen. ........ = 4'75 



7-60 



— atomic capacity of aqueous vapour. . = 1*75 



.'. caloric evolved by the combustion of one 



: atom of hydrogen = 5*85 



Atomic capacity of carbonic acid = 0-414 



H- atomic capacity of lime = 1*06 



1-474 

 'r atomic capacity of carbonate of lime = 1-700 



- 0-226 

 or 0-226 of caloric are absorbed. 



From the table, the most inflammable bodies appear to have 

 the smallest capacities, and may therefore be supposed to con- 

 tain the smallest quantity of caloric : thus oxygen has the 

 greatest capacity : the capacity of hydrogen is large, when com- 

 pared with that of the metals ; since, however, it is highly elas- 

 tic, its capacity must be much greater than it would be if 

 hydrogen were reduced to the solid state. Gold, silver, and 

 mercury, have a larger capacity than copper; copper than iron, 

 tin, or zinc ; these larger than that of sulphur or carbon. Hence 

 those bodies which possess the highest electro-negative energy, 

 or are attracted most powerfully by the positive pole, or which 

 have the greatest tendency to the earth, have the greatest 

 attraction for caloric. These facts may be applied in investiga- 

 tion without reference to any hypothetical views. In compounds 



