58 Remarks on Inertia. 



gravity ? The body is altogether without directive power, 

 and yields itself to the impulse of gravitation without choice 

 and without resistance ; and how this state of things should 

 diminish its velocity, and in such a remarkable degree too, 

 (from passing over any distance whatever in an instant, to a 

 few feet,) we confess that we cannot conceive. We conclude 

 then, that Mr. B. did not intend to express what we under- 

 stand by inertia ; and after some examination of the different 

 applications of the term throughout the essay, we think that 

 Mr. B. conveys by it the notion of agency. Thus, when we 

 are informed that inertia prevents the instantaneous descent 

 of bodies, from any height, we are to look upon inertia 

 as an active force striving to retard the fall of bodies, 

 and increasing in intensity of action, as the descending bo- 

 dies approach the centre of attraction. Now, if this assump- 

 tion, as to the meaning of the term, be supported by fact, 

 there will be some appearance of consistency and truth in 

 the theory : but we venture to say that it is entirely ground- 

 less ; and that by the inertia of matter, the only thing which 

 can be understood as having a real existence in nature, to 

 which it corresponds, is the absence of all action ; just as 

 darkness is the absence of light. 



It may serve to show the real strength of Mr. B.'s theory, 

 to substitute the proper meaning of the term, inertia, in other 

 places where it is used. " A ball of one pound will fall from 

 a height of sixteen feet to the earth in one second ; a ball of 

 one hundred pounds will descend over the same space in the 

 same time :" we have been in the habit of thinking that the 

 point to be explained in the instance just given, is why the 

 large ball should fall as fast as the smaller one ; since large 

 bodies are moved with greater difficulty : and we believed 

 the thing fully accounted for, from the known fact that grav- 

 itating forces increase as the quantity of matter ; and hence, 

 although one of the bodies were a hundred fold larger than 

 the other, and therefore moved with greater difficulty, as the 

 gravitating force was increased in the same proportion, the 

 velocity of the greater body must just equal that of the smal- 

 ler. Mr. B., however, views this matter in a different light, 

 and considers it necessary to give a reason why the one hun- 

 dred pound ball, does not fall faster than that which weighs 

 only one pound : — his reason is, " because the impeding 

 quality, inertia, increases as the attracting quality weight :" 

 ■ — that is, the one hundred pound ball, is one hundred times 



