24 INDUCTION. 



remarkably different,) is a case in point. There is an 

 extraordinary similarity running through the proper- 

 ties, considered generally, of certain substances, as 

 chlorine, iodine, and brome, or sulphur and phospho- 

 rus ; so much so that when chemists discover any new 

 property of the one, they not only are not surprised, 

 but expect, to find that the other or others have a 

 property analogous to it. But the hypothesis that 

 chlorine, iodine, and brome, or that sulphur and 

 phosphorus, are the same substances, would, no doubt, 

 be quite inadmissible 



I do not, like M. Comte, altogether condemn 

 those who employ themselves in working out into 

 detail this sort of hypotheses ; it is useful to ascertain 

 what are the known phenomena to the laws of which 

 those of the subject of inquiry bear the greatest, or 

 even a great analogy, since this may suggest (as in the 

 case of the luminiferous ether it actually did) experi- 

 ments to determine whether the analogy which goes 

 so far does not extend still further. But that in 

 doing this, men should imagine themselves to be seri- 

 ously inquiring whether the hypothesis of an ether, 

 an electric fluid, or the like, is true ; that they should 

 fancy it possible to obtain the assurance that the phe- 

 nomena are produced in that way and no other; seems 

 to me, I confess, as unworthy of the present improved 

 conceptions of the methods of physical science, as it 

 does to M. Comte. And at the risk of being charged 

 with want of modesty, I cannot help expressing asto- 

 nishment that a philosopher of the extraordinary 

 attainments of Mr. Whew ell should have written an 

 elaborate treatise on the philosophy of induction, in 

 which he recognises absolutely no mode of induction 

 except that of trying hypothesis after hypothesis until 

 one is found which fits the phenomena ; which one, 



