1820.] the Atomic Theory. 339 



but if the sulphuret, composed, according to Vauquelin, of 100 

 metal + 33-3 sulphur, be considered as a protosulphuret, the 

 weight of the atom of iridium will be found as 33*3 : 100 :: 2 

 (weight of an atom of sulphur) : 6 atom of iridium. 



65. Aiithnoiii/. — Antimony forms sev'eral oxides, the lowest of 

 which, according to Berzelius, is composed of 100 metal + 18*6 

 oxygen ; ihe next of 100 + 27-9; and a third of lOO + 37-2. 

 Now, these numbers are to each other as 2, 3, 4 ; hence, the 

 first appears to be a deutoxide ; therefore, 18-6 : lUO :: 2 

 (weight of 2 atoms oxygen) : 10-75 weight of the atom of anti- 

 mony. But Dr. Thomson makes the atom of antimony 5-625, 

 taken from his analysis of the sulphuret of antimony, which he 

 finds composed of 100 antimony + 35-572 sulphur. Noav, 

 35-572 : 100 :: 2 : 5-625. 



QQ. Molybdenum. — From the experiments of Bucholz there 

 seems to be three oxides of this metal. The greatest, molybdic 

 acid, composed of 100 metal + 50 oxygen; the next, molybdous 

 acid, of lUO metal + 33-3 oxygen. The third has not been ana- 

 lyzed ; but as oxygen combines in an arithmetical progression, 

 the difference between 50 and 33*3 = 16-7 taken from 33-3 will 

 give the next lowest term to 33-3 = 16-6 oxygen. 



But independent of this step 33-3 : 50 :: 2 : 3 nearly. Hence 

 the oxide of 100 metal and 33-3 oxygen is a deutoxide, by means 

 of which we may obtain the atom of molybdenum. 



As 33-3 : 100 :: 2 (weight of two atoms oxygen) : 6, weight of 

 the atom of molybdenum. 



67. Tiihgsteii.— It ifi proved, by experiment of Messrs. D'El- 

 huyarts, Bucholz, and Berzelius, that tungslic acid is composed 

 in the proportion of 100 tungsten and 25 oxygen; and Berzelius 

 has also shown that brown oxide of tungsten contains very 

 nearly two thirds the quantity of oxygen that exists in tungstic 

 acid, or that it is composed of about 



Tungsten 100-0 



Oxygen 16-6 



The brown oxide may, therefore, be properly considered a 

 deutoxide, because 16-6 oxygen : 25 oxygen in tungstic acid :: 

 2 : 3. From this consideration the atom of tungsten will be 12; 

 because 16-6 : 100 :: 2 (atoms oxygen) : 12 the atom of tungsten. 



68. Colnrubium. — This metal forms with oxygen but one 

 known oxide, consisting of 100 metal -\- 5-485 oxygen. Then as 

 5-485 : 100:: 1 : 18-23, weight of the atom of cohmibium. 



69. Nickel. — We are acquainted with two oxides of nickel .;; 

 the first, from a mean of the experiments of Tupuli, Rotlioff, and 

 Berzelius, is composed of 100 metal + 27-6 oxygen; the second, 

 W the experiments of llothoff, of 100 nickel + 41 oxygen.- 

 These numbers are in the following ratio: 27-6 : 41 :: 2 : 3. 

 Hence, 2 and 3 being the lowest proportional integers of 27*6 

 and 41, wc may take the 2 as rcpresehting two atoms, and the 



y 2 



