354 GRAVITY. SECT. XXXIV. 



A body acquires heat in the exact proportion that the adjacent 

 substances become cold, and when heat is absorbed by a body it 

 becomes an expansive force at the expense of those around that 

 contract, but it is not lost. In chemical action at a distance the 

 principle of the conservation of force is maintained, for a chemical 

 action may be produced miles away from an electro-magnet, per- 

 fectly equivalent to the dominant chemical action in the battery. 

 The two electricities are developed in equal proportions, which 

 may be combined so as to produce many changes in their respec- 

 tive relations, yet the sum of the force of one kind can never be 

 made in the smallest degree either to exceed or to come short of 

 the sum of the other. Experimental research proves that the con- 

 servation of force is an unalterable law of nature " a principle 

 in physics as large and sure as that of the indestructibility of 

 matter or the invariability of gravity. No hypothesis should be 

 admitted, nor any assertion of a fact credited, that denies this 

 principle. No view should be inconsistent or incompatible with 

 it. Many of our hypotheses in the present state of science may 

 not comprehend it, and may be unable to suggest its conse- 

 quences, but none should oppose or contradict it." 



Having thus expressed his conviction of the truth of this great 

 principle, Dr. Fajaday considers the case of gravity, and con- 

 cludes that " the definition of gravity as an attractive force be- 

 tween the particles of matter varying inversely as the square of 

 the distance, while it stands as a full definition of the power, is 

 inconsistent with the principle of the conservation of force." 

 For while in this definition the principle is maintained of the 

 constancy of the force at the same distance, it implies a creation 

 of force to an enormous amount when the distance is diminished, 

 and an equal amount annihilated when the distance is increased, 

 " an effect," he says, " which is equal in its infinity and its 

 consequences with creation, and only within the power of Him 

 who creates." He continues, " It will not be imagined for a 

 moment that I am opposed to what may be called the law of 

 gravitating action, that is, the law by which all the known 

 effects of gravity are governed ; what I am considering is the 

 definition of the force of gravitation. That the result of one 

 exercise of a power may be inversely as the square of the dis- 

 tance, I believe and admit ; and I know that it is so in the case 

 of gravity, and has been verified to an extent that could hardly 



