

1818.] the Atoms of Chemical Bodies. 349/ 



Weight of an atom. 



83 Protoxide of antimony 6-625 



84 Deutoxide of antimony 20-875 ? 



85 Peroxide of antimony 7*625 



86 Chromium 3-500 



87 Chromic acid 6-500 » 



88 Molybdenum 6-000 ° 



89 Protoxide of molybdenum 7-000 



90 Deutoxide of molybdenum 8*000 



91 Molybdic acid 9*000 



92 Tungsten 12*000 



93 Protoxide of tungsten 14*000 



94 Peroxide of tungsten 15*000 t 



obtained by heating protoxide or peroxide to redness. The 

 oxygen in it is to that in the protoxide as 4 to 3. Hence we 

 may conceive it to be a compound of 3 atoms metal -f 4 atoms 

 oxygen : this would make its weight 20*875 ; but this seems too 

 complicated a compound to be the true representation of the 

 composition of this oxide. Further experiments are requisite to 

 elucidate this subject. 



n Chromate of lead, according to Berzelius, is composed of 

 100 acid + 213*841 protoxide of lead; and chromate ofbarytes, 

 of 100 acid + 149*066 barytes. From the first salt, it follows 

 that an atom of chromic acid weighs 6*547 ; from the second, 

 that it weighs 6*541. I have, therefore, taken 6*5 as the true 

 weight. As there are three oxides of chromium, it is probable 

 that the peroxide or chromic acid contains 3 atoms of oxygen. 

 On that supposition an atom of chromium will weigh 3*5, as in the 

 table. 



° Molybdate of lead, according to the analysis of Berzelius, is 

 composed of 100 molybdic acid + 155*15 protoxide of lead 

 Now 155*15 : 100 :: 14 : 9*023. Hence 9 appears to be the 

 weight of an atom of molybdic acid. Now as molybdenum forms 

 three different oxides, I conceive the first to be a compound of 

 1 atom molybdenum + 1 atom oxygen ; the second, of 1 atom 

 molybdenum + 2 atoms oxygen ; and the third, of 1 atom mo- 

 lybdenum + 3 atoms oxygen. Hence the weight of an atom 

 of molybdenum and of its three oxides, as given in the table. 



p • Tungstate of lime, according to Berzelius, is composed of 

 100 tungstic acid + 24*12 lime. Now 24*12 : 100 :: 3*625 : 

 15*03. I, therefore, consider 15 as the weight of an atom of 

 tungstic acid. It seems proved that tungstic acid is a compound 

 of 4 metal + 1 oxygen. If we divide 15 in this ratio, we get 

 12 metal + 3 oxygen. Hence an atom of tungsten must 

 weigh 12; and tungstic acid must consist of 1 atom metal + 

 3 atoms oxygen. According to Berzelius, brown oxide of tung- 



