50 Royal Society. 



not of the particles, the inference should have been, that there 

 is one direction in which waves cannot he transmitted ; or, in 

 other words, that the (Ether is opake in one direction. 



2nd. But I am unable to discover on what ground it is 

 stated that v' is impossible. I see no reason why we may not 

 say with equal truth that u' is possible, and v and v" impossi- 

 ble; in which case ihe inference is, that the (Ether is trans- 

 parent in one direction only. 



3rd. After all, it appears to me that the implied impossi- 

 bility of some one (or two, as the case may be) of the quantities 

 u u' v" has reference to a fact distinct from either of these in- 

 ferences, viz. the instability of the medium when the forces vary 

 according to the Newtonian law. If u' be impossible, as is 

 asserted in the memoir referred to, it shows that the sines and 

 cosines of all angles in which v' occurs ought to have been 

 written in the form of exponentials, and that some equation 

 has been integrated by sines or cosines which ought to have 

 been integrated by exponentials. Hence it follows that a 

 vibrating motion of the particles is impossible, and that the 

 particles of the whole medium are in a state of either neuter 

 equilibrium, or unstable. In either case it is unfit for the 

 transmission of light, and results derived from it are, if at all, 

 only accidentally applicable to the phsenomena of nature. 



Cambridge, May 3, 1842. 



XII. Proceedings of Learned Societies. 



ROYAL SOCIETY. 



[Continued from vol. xx. p. 512.] 



March 17, r |^HE reading of a paper, entitled " Contributions to 



1842. ■*■ the Chemical History of the Compounds of Palla- 

 dium and Platinum," by Robert Kane, M.D., M.R.I.A., communi- 

 cated by Francis Baily, Esq., V.P.R.S., was resumed and concluded. 



The author states it to be his object, in this and in some subse- 

 quent papers, to examine specially the composition and properties 

 of the compounds of palladium, platinum, and gold ; and to ascertain 

 how far they agree, and in what they differ, as to the laws of com- 

 bination to which these compounds are subjected. He commences 

 with the investigation of the compounds of palladium, employing for 

 that purpose a portion of that metal with which he was furnished by 

 the Royal Society out of the quantity bequeathed to the Society by 

 the late Dr. Wollaston. He describes the mode of obtaining the 

 protoxide of palladium, and enters into the analysis of the hydrated 

 oxide, the black suboxide, and the true basic carbonate of that metal ; 

 detailing their properties and the formulae which express their mode 

 of composition. The chlorides of palladium form the next subject of 

 inquiry ; and the author concludes from his experiments that the loss 

 of chlorine which the protochloride undergoes, when kept for some 



