298 D.'s St'coiid licphj to C. 



cult to try. Overturning these instances would aftord C. the 

 gratification — a gratification that would not be lightly valued — 

 of upsetting " Mr. H. in his prophetic character." Would 

 not such a course also be much more " honourable," much 

 more scientific, and much less liable to the charge of " mean- 

 ness" and turpitude, than indulging in general clamour, ca- 

 lumny, and misrepresentation ? 



C. has, it must not be denied, stated one numerical objection, 

 preparatory, I suppose, to a general refutation. It is this, that 

 Mr. Herapath's calculation of the composition of water differs 

 from like calculations of some chemical writers. Mr. H. by his 

 theoi'y from the well known fact, that two in volume of hydrogen 

 unite with one in volume of oxygen to form water, finds that 

 two particles of oxygen unite with one of hydrogen. This re- 

 sult he has, as far as it can be expected from the experiments 

 in their present state, confirmed by the observed capacities of 

 Crawford, Annals for Sept. 1821, p. 211 ; and he has i'urther 

 shown, that it is possible by correct experiments of this kind to 

 confirm or refute his views of the composition of water. Some 

 chemical writers, however, have concluded, from the proportion 

 (two to one) of the component volumes, that two particles of 

 hydrogen unite with one of oxygen ; and others, I beKeve, have 

 thought that a particle of water consists of one of each. If you 

 ask these writers for a proof of either of these proportions, they 

 can give you none, nor any reason why it should be one with 

 one, two with one, or ten with one, in preference to any other 

 proportion. They tell us experiments prove that airs combine 

 in simple multiples of volume, and other bodies usually in 

 simple multiples of weight ; from which they very justly con- 

 clude that the elementary particles likewise combine in certain 

 definite numerical proportions; but what these proportions are, 

 it is impossible they could tell us frrm the multiples of weight 

 or volume alone, unless the relative number of particles in equal 

 weights or volumes was known, which they all confess they have 

 no data for determining. The precise proportion therefore of 

 one or of two particles of hydrogen to one of oxygen, is purely 

 hypothetical, without any Ibundation in experiment; and tliis 

 C, if he has any knowledge of chemistry, ought to have known. 



C.'s subsequent paragraph, producing calculations for rea- 

 soning, I have already considered. It is almost as fine a spe- 

 cimen of his "modesty" as of his loiowledge. 



" I have already proved," quoth C, " by extracts from his 

 works, that on the laws of collision Sir I. Newton's opinions 

 directly, both in words and meaning, contradict Mr. Hera- 

 path's." Has C. then, it may be asked, disproved D.'s quota- 

 tions from Newton's Principia? No. — Flas he shown these 



(juotations 



