48 On the Daltonian Theory of [July, 



Weight of an atom. 



49. Silver 12*fil8y 



50. Mercury 25*000 l 



51. Palladium 14*204 " 



52. Copper 8-000 b 



53. Iron 6666 c 



54. Nickel 7*305 d 



55. Tin 14*705 e 



caustic alkali ; the second by digesting oxy-sulphate of platinum 

 in caustic alkali. The first oxide is black, the second yellowish 

 brown. (Liirbok i Kemien, ii. 421.) The results obtained by 

 Chenevix do not differ materially from those of Berzelius. 



y We only know one oxide of silver, which therefore I con- 

 sider as a protoxide. By the experiments of Berzelius it is 

 composed of 100 metal + 7*^25 oxygen. This corresponds 

 with the preceding analysis of Bucholz. {Ami. de Chhn. 

 lxxviii. 1 15.) 



1 This nearly agrees with the experiments of Sefstrom, as 

 related by Berzelius. He found the protoxide a compound of 

 100 metal + 5*39 Oxygen, the peroxide of 100 metal + 7*99 

 oxygen. (iArbok i Kemien, ii. 317) Fourcioy and Thcnard 

 found the protoxide composed of 100 metal + 4'1G oxygen, 

 the peroxide of 100 metal + 8*21 oxygen. (Mem. d' Arcueil, 

 ii. 168.) I have taken 4 as the intermediate proportion of oxygen 

 in the protoxide, which must be very near the truth. 



a Berzelius states the oxide of palladium to be composed of 

 100 metal + 14 08 oxygon. (Larbuk i Kemien, ii. 405.) The 

 appearances of the metal when dissolving in acids leads me to 

 consider this oxide as a peroxide. If it be a protoxide the weight 

 of an atom of palladium will be 28*408. 



h It has been ascertained by very exact experiments that the 

 protoxide of copper is composed of 100 metal + 12*5 oxygen, 

 and the peroxide of 100 metal + 25 oxygen. (Ann. de Cliim. 

 lxxviii. 1070 



c We know two oxides of iron ; the first composed of 100 

 metal + 30 oxygen, the second of 100 metal + 45 oxygen. 

 Hence the first must be a deutoxide. 



A We are acquainted with two oxides of nickel ; the first, 

 from a mean of the experiments of Taputi, Rolhoff, and Berze- 

 lius, is composed of 100 metal + 27'6 oxygen; the second 

 appears from Rolhoff s experiments to be composed of 100 

 metal 4- 41 oxygen. Hence the first must be a deutoxide, or a 

 compound of I atom of metal with 2 atoms of oxygen. This 

 gives us the number in the table. 



e I am acquainted with two oxides of tin ; the first composed 



