1826. J Mr. Rami/*s Reply to Dr. Thomson. 19$ 



hydrogen. Let us call the specific gravity of hydrogen y, and ^ 

 that of oxygen x, it follows from the above statement that 



y + I = 0-625. 



This is an indeterminate equation, which of course discloses 

 nothing with regard to the ratio ofy to x. They admit of an 

 infinity of values. If we put y = 0*073, we shall find x= 1'104, 

 which were nearly the numbers pitched on by Gay-Lussac. We 



shall find x = 1*111 1 if we make y = 0'0694, but that is one of 

 the very points in dispute. Therefore there is no inconsistency 

 in supposing that the specific gravity of vapour is 0*625, and yet 

 that Dr. Front's hypothesis is unfounded. 



Dr. Prout proposed his views, as a probable conjecture, not 

 inconsistent with the established facts of chemistry, and, there- 

 fore, deserving of further inquiry. Dr. Thomson adopted them 

 as completely proved, and seems to think that they must be 

 admitted to be true, if they cannot be proved to be false. He 

 accordingly introduced them into his System, and did not scruple 

 in any instance to modify experimental results so as to corre- 

 spond with them. Dr. Thomson's System has long been consi- 

 dered a standard work in chemistry, and probably has contributed 

 more to diffuse correct views of chemical science than any 

 treatise that ever was published in Britain. I think it is deeply 

 to be regretted, that in a work in every other respect so valuable, 

 most of the experimental results should be vitiated, by modifying 

 them to suit an hypothesis, which, whether it be true or false, will 

 tend to retard the science, if adopted prematurely and on insuf- 

 ficient evidence. 



Dr. Thomson has well remarked that this doctrine gives a 

 mathematical precision to chemical research, which the most 

 sanguine cultivators of chemical science could scarcely have 

 anticipated. But just in proportion to the importance of these 

 views, is it necessary rigidly to examine the evidences of their 

 truth. The evidences hitherto adduced appear to me, for the 

 reasons already stated, to be by no means satisfactory. Some 

 of them are even inconsistent with the truth of the hypothesis. 

 I would not, however, be understood as asserting that Dr. Front's 

 views are incorrect. I think it is still a matter open for inquiry ; 

 and it is a very remarkable circumstance, that though more than 

 ten years have now elapsed since Dr. Prout's paper was pub- 

 lished in the Annals, no chemist, except Dr. Thomson, should 

 have engaged in any experimental researches on a subject so 

 highly important. 



VVhile I thus freely state my objections to the reasonings. of 

 Dr. Thomson, I hope I have done so with that deference which 

 is due to his talents and experience. The subject evidently 



New Series, vol. xi. o 



