182L] Observations on Mr. Herapath's Theory i 419 



instances (if the words are taken in their usual sense), true con- 

 clusions may be brought out from false principles by correct 

 reasoning. If, for instance, the errors on each side should 

 exactly compensate each other, the result will be correct though 

 the foundation be erroneous. Frequently too there are several 

 ways by which a fact may be accounted for by correct reason- 

 ings, yet all those ways cannot be the true mode of accounting 

 for it. The argument in relation to the nature of muriatic acid 

 is a striking instance. The principles, therefore, on which the 

 reasoning is founded in those cases in which the proper mode 

 of explaining the facts is not adopted, are incorrect, though the 

 fact be itself true. Indeed it might be said to have become 

 almost a proverb, that the conclusion may be true though the 

 foundation of the argument is false. 



But to return, I apprehend that one of the first objections to 

 the theory which will offer itself to the mind of an inductive 

 philosopher, is its assuming to be so entirely founded on mathe- 

 matical demonstration. The most important question proposed 

 is, whether heat is a peculiar motion of the particles of bodies. 

 Now it is in the nature of things impossible to demonstrate this 

 to be the fact merely by mathematics. Even if it should be 

 proved, that if the fact be first assumed, the phenomena of heat 

 will be governed by certain laws, and that these laws are the 

 same with those which experiment prove actually to exist, and 

 this be shown to be the case universally, a strong argument 

 would certainly be raised that the phenomena of heat are in fact 

 produced by this peculiar kind of motion ; but if any one should 

 therefore assume that he has mathematically demonstrated that 

 heat and the peculiar motion are the same, the assumption will 

 be both illogical and incorrect. One thing is, however, abso- 

 lutely necessary even to raise an argument in its favour ; namely, 

 that the laws discovered by the mathematical reasoning and by 

 experiment, should be indentical in all cases ; — a circumstance 

 which it must be always most difficult to prove. In this parti- 

 cular case, I will examine whether it is not sufficiently easy to 

 prove the contrary. 



Experiment has clearly shown that caloric, or the immediate 

 cause of heat, whatever it may be called, cannot be destroyed.* 

 However, under particular circumstances, it may become for a 

 time imperceptible, it can be again developed, and so be shown 

 to have continued its existence ; if, therefore, heat and motion 

 be identical, motion cannot be destroyed. This, I apprehend, 

 the experience of every day, in addition to mathematical argu- 

 ment, tells us is untrue. We all every day see motion generated 

 and destroyed. Nor can this objection be answered by a sup- 

 posed difference in the nature of the motion, as we cannot even 

 conceive of any difference in motions, except that which is made 

 by their quantity and direction. 



Again ; heat is communicated from one object to another at 



2 k2 



