232 ON CHEMICAL ENERGY. 



Especially are we forced to couelude, from the fate of x>ast tlieorictS, 

 that chemical phenomena must be explained by their own inter-relations; 

 that is, must be logically arranged. The use of analogies from other 

 fields of natural science has indeed often led to suppositions which for 

 the moment vseemed satisfactory; on trial, liowever, such analogies have 

 always proved themselves more a drawback than a help, since they 

 hindered the unbiased comprehension of facts, and they could not (or 

 will not in the future) be cast aside without a great struggle and con- 

 siderable sacrifice of time and labor. 



It is scarcely needful at present to prove that the several provinces 

 of quantitative science ]iossess in a single conception both the principle 

 which distinguishes them and that common principle which unites them, 

 namely, the conception of energy. Mechanical energy is distinct from 

 thermal. Similarly, chemical energy is distinct from electrical; and in 

 each province progress can only be made by studying the various prop- 

 erties which the form of energy under examination possesses. 



At the same time, however, the laws which determine the correla- 

 tion and conservation of energy constitute the only bond which unites 

 the various fields. If heat could not be changed into mechanical energy 

 and chemical into electrical, these provinces would stand distinct and 

 isolated from each other; and neither thermo-dynamics nor electro- 

 chemistry would be possible. This shows that progress in the scien- 

 tific conception of chemical i)henomena depends upon primarily deter- 

 mining the sevinal pro[)erties of chemical energy as such, and then its 

 relation to other forms of energy. This done, we will be able to cope in 

 a scientific manner with each chemical process, no matter whether it 

 leads to other chemical changes or causes the appearance or destruc- 

 tion of other forms of energy. 



The knowledge of the laws of chemical energy is not only scientific- 

 ally but also practically of the greatest interest. All energy, which is 

 employed in accomplishing the various purposes of industry, is derived 

 from chemical sources, the combustion of fuel. Besides, each step that 

 we take, every word tliat we speak, in fact every thought formulated 

 by our brain, leads to sources of chemical energy; animals and plants 

 throughout their whole existence are based primarily upon chemical 

 energy and its laws, and the ultimate problems of biology are in every 

 respect chemical. 



All forms of energy have this in common, that they may be resolved 

 into two factors, both of which have definite properties. 'J'he one, 

 which we call intensity, determines whether the energy may remain at 

 rest or must undergo an exchange. Thus, for instance, the factor of 

 intensity for heat is temperature, since we know that two bodies can be 

 at rest with reference to their heat only when their temperatures are 

 equal. The second factor we call capacity; it determines how much 

 energy at a given intensity is present in the object under consideration. 

 With heat, for instance, this is called heat capacity. 



