S60 On the Cause of Chemical Proportiom. [Ma^, 



ought to contain 18-49. Tiiis approaches very neaily to the result 

 obtained by the preceding experiment. 



As all the earths must be classed among oxides which contain 

 more than one volume of oxygen, it is probable that they contain 

 in general two volumes, in that case the volume of yttrium will 

 weigh from 876-42 to 881-66. 



I ought to observe that the yttria employed in these experiments 

 contained no glucina, but I was not able to deprive it entirely of the 

 manganese, a little of which is present in gadoliuite. 



31. Glucinum (Gl). — Unknown. 



32. Alum'mum (Al). — 1 have proved in another memoir that 

 alumina ctmtains 46*726 per cent, of oxygen. In alum the oxygen 

 of the alumina is to that of the potash as 3 : 1. Hence it seems to 

 fallow that alumina contains three volumes of oxygen : but as the 

 phenomenon is equally explicable on the supposition that alum 

 contains three volumes of aluminum for one volume of potassium, 

 the observation proves nothing with respect to the weight of a 

 volume of aluminum. If we suppose alumina to be Al + 2 O, the 

 volume of aluminum will weigh 228 ; if we suppose it Al + 3 O, 

 the volume will weigh 342. 



33. Mugnesiuin (Ms). — Experiments on the composition of sul- 

 phate and muriate of magnesia indicate in that earth from 38-3 or 

 38'8 to 39'872 per cent, of oxygen. If we suppose magnesia to be 

 Ms + 2 O, the volume of magnesium will weigh 315*46 j in its 

 minimum 301*68, and in its maximum 321-93. 



34. Calcium [C-d). — Lime contains, according to the analysis of 

 the muriate and carbonate of lime, 28*169 per cent, of oxygen. 

 Therefore if lime be Ca + 2 0, the volume of calcium must weigh 

 510-2. 



35. Strontium (Sr). — From the analysis of the muriate of this 

 earth made by Sir H. Davy, 100 parts of muriatic acid are neu- 

 tralized by 209 parts of strontian. Hence it follows that the earth 

 contains 14*09 per cent, of oxygen. Therefore if strontian be 

 Sr + 2 O, the volume of strontium will weigh 14 18- 7 16. 



36. Barytium (Ba). — From the analyses of the sul|)hate and 

 muriate of i)arytes, the earth contains 10-47 per cent, of oxygen. 

 Now, supposing barytes to be Ba + 2 O, the volume of barytium 

 will be 1709-1. 



37. Sodium (So). — 100 parts of sodium combine with 34-52 

 parts of oxygen, and the peroxide contains 1^ times as much. 

 Hence it follows that soda is So + 2 Oj and the volume of sodium 

 must weigh 579-32. 



38. Potassium (Po). — 100 jiarts of this metal combine with 

 2045 of oxygen in potash, and with three times as much in the 

 peroxide. Hence potash should be I'o + 2 O, the peroxide Po + 

 6 O, and tlie protoxide Po + O ; and a volume of potassium 

 should weigh 978. 



In publishing this attempt to determine the specific weight of 

 <'ach •elementary substanrc, suj)posing it in the state of gas, 1 ought 



