228 KANSAS CITY REVIEW OF SCIENCE. 



With these propositions before us, let us look at nature and see if we are 

 justified in accepting them. 



From the densest of metals to the rarest of gases there is a law of contraction 

 and expansion. All bodies are expanded by the application of heat. Here we 

 have the repellent. They are all contracted on its withdrawal. They all have 

 a capacity for heat. Each after its own measure absorbs heat without increase 

 of temperature. They may all be vaporized, or thrown into gaseous form. But 

 in this change an immense amount of heat aflQliates with the atoms of matter. 

 And in this condition they fill many times the space formerly occupied. Here 

 we have both the affiliation of heat with the matter, and the expansive power of 

 heat in separating the matter. The^more the heat is applied, the more room is 

 demanded; the expansive force, the self-repellent force, bursting the confines 

 and filling vast regions of space. This is found everywhere in nature. The 

 binding force that binds substances together is under law, each substance having 

 a measure of its own. Each having a law of its own with regard to the rise of 

 temperature, each a law of its own as to the amount of heat it appropriates with- 

 out rise of temperature, and a law of its own as to the amount of heat required 

 to accomplish certain results. But in all cases heat is king. It unlocks every 

 barrier. It determines every new condition. It dissipates into the realms of the 

 invisible, masses of matter, by enshrouding itself in gauzy garments too attenu- 

 ated for observation. In the taking up of these particles of matter we see the 

 affinity between heat and matter. In the carrying of them away we see the repel- 

 lent power of heat. Were it not for the attraction that causes the atmosphere to 

 press as an ocean on the surface of the earth, this self-repellence would dissipate 

 it through all space. In everything we have these two elements, heat and matter, 

 differently compounded. In metals we have most matter and least heat. In 

 liquids less matter and more heat. In gases we have least matter_and most heat. 

 And metals are more or less re-fractory, liquids more or lees volatile, and gases 

 more or less attenuated, in proportion as the one element or the other, heat or 

 matter, predominates in its composition. 



Wherever you touch the science of chemistry you find these positions illus- 

 trated and confirmed. Here every g?.s, simple or compound, has its appropriate 

 measure of heat. Two simple gases have more heat than their compound re- 

 quires — so in their union heat is given off. All chemical changes' are accompa- 

 nied by corresponding changes of heat. Our theory would require this. Chem- 

 ical combinations pr./duce heat, because here the more attenuated resolve them- 

 selves into the more compact, and heat is set free. Chemical decomposition 

 causes a disappearance of heat, because here the one compact substance is re- 

 solved into two that are more volatile, heat being the element that is necessary to 

 the new condition. We have this law, the combination of any two bodies chem- 

 ically, is attended by the evolution of a quantity of heat equal to that which dis- 

 appears in their separation: 



Most chemical changes are complex. In them we have both decompositions 

 and recompositions. Here both the minus and the///yj come in, so we have this 



