260 Prof, WheweWs Demonstration 



Art. VII. — A Letter to William Whewell, Professor of Moral 

 Philosophy in the University of Cambridge, England, in 

 reply to certain allegations and arguments advanced in a 

 pamphlet entitled a Demonstration that all Matter is Heavy ;* 

 by Robert Hare, M. D., Professor of Chemistry in the Uni- 

 versity of Pennsylvania. 



1. Dear Sir — I thank you for your kind attention in sending 

 me a copy of your pamphlet entitled a " Demo7istration that 

 all Matter is Heavy ^"^ comprising a communication made to the 

 Cambridge Philosophical Society. 



2. I conceive that to demonstrate that all matter is heavy, is, in 

 other words, to prove that all matter is endowed with attraction of 

 gravitation, or that general property which, when it causes 

 bodies to tend towards the centre of the earth, is called weight. 

 Hence to assert that all matter is heavy, is no more than to say, 

 that attraction of gravitation exists between all or any masses of 

 raaiter.f 



3. You say, " it may be urged that we have no difficulty in con- 

 ceiving of matter which is not heavy." I have no hesitation in 

 asserting, that there should be no difficulty in entertaining such a 

 conception ; since I cannot understand why any two masses 

 may not be as readily conceived to re'pel as to attract each other, 



, or neither to attract nor to repel. Is it not easier to imagine two 

 remote masses indifferent to each other, than that they act upon 

 each other ? Is any thing more difficult to understand than that 

 a body can act where it is not ? 



4. It is also mentioned by you, that it may be urged " that iner- 

 tia and weight are two separate properties of matter. ^^ Now I will 

 not only urge, but also, with all due deference, will undertake to 

 show, that the existence of inertia may as well be proven, and 

 its quantity estimated, by means of repulsion as by means of 

 attraction. 



* Transactions of the Cambridge Philosophical Society. 



t We have thought that Dr. Hare's letter would be better understood by our 

 readers, if we republished the " Demonstration" of Prof. Whewell, as it has prob- 

 ably been seen by few persons in America. It will accordingly be found in full at 

 the end of Dr. Hare's letter. — Eds. 



