1813.] Definite Proportions in Chemical Combinaiicms. 49 



Weight of an atom. 



56. Lead 25*974 f 



57. Zinc 4-315 * 



58. Bismuth 8*994 h 



59. Antimony 11*111 • 



of 100 metal -f 13*6 oxygen, the second of 100 metal + 27*2 

 oxygen. Berzelius describes an intermediate oxide, which he 

 calls the white oxide, and which is composed of 100 metal + 

 20 - \ oxygen. {Larlok i Kemien, ii. 253.) Granting the existence 

 of this oxide, it is evident that the first must be composed of 1 

 atom metal and 2 atoms oxygen, or that it is a deutoxide. 



' We know three oxides of lead ; namely, the yellow, the 

 red, and the brown, composed of 100 metal, united with 7 7> 

 1 1*55, and 15*4 oxygen. Now these numbers are to each other 

 as 2, 3, 4. Hence the yellow oxide must be a compound of 1 

 atom metal and 2 atoms oxygen ; which gives us the weight of 

 an atom of lead as in the table. 



g In my System of Chemistry I have stated two oxides of zinc 

 on the authority of Clement and Desormes; but from examining 

 the salts of zinc 1 have satisfied myself that no such oxide as 

 their protoxide exists. Hence I consider the white oxide of zinc 

 as a compound of 1 atom metal and 1 atom oxygen. Berzelius 

 iound it a compound of 100 metal + 24*4 oxygen ; Davy, of 

 100 metal -f- 21*951 oxygen : my analysis gave me 100 metal 

 + 23*5 oxygen, which is nearly a mean of the other two. I 

 have chosen 23*175 as probably coming nearest the truth. 



h Bismuth forms only one known oxide, which therefore I 

 conceive to be a compound of I atom of metal and 1 atom of 

 oxygen. By my analysis it is composed of 100 metal 4- 11*300 

 oxygen; by Lagerhjelm's, of 100 metal + 11*2/5 oxygen 

 [Berzelius, Larook i Kemien, ii. 175) ; by Mr. John Davy's, 

 of 100 metal + 11*111 oxygen. The mean of these gives 

 1 1 229 for the oxygen. Hence the number in the table. 



1 We know two oxides of antimony. The first, according to 

 Mr. John Davy, is a compound of 100 metal + 17*647 

 oxygen; according to Berzelius, of 100 metal + 18*6 oxygen • 

 the second, according to Davy, of 26*471 oxygen 4-100 metal; 

 ■wording to Berzelius, of 100 metal + 27*9 oxygen. Berzelius 

 describes a third oxide, which he calls the yellow oxide, and 

 states as a compound of 100 metal + 37*2 oxygen. (Liirlok i 

 Kemien, ii. 159.) These numbers are to each other as 2, 3, 4. 

 Hence I consider the first as a deutoxide, and that an atom of 

 antimony is to an atom of oxygen as 100 to 9. Hence the 

 number in the table. 



Voi. II. N° I. D 



