198 MEMOIll OF DJl. DALTON, AND 



parts of magnesia, and 1394 parts of vitriolic acid with 734 

 parts of alumina; the proportionate amount of the alum 

 formed will then be 1394 : 734=1000 : 526, which is not the 

 proportion of the neutral but the common alum. (§ XXI.) 

 The quantity of the alkaline earth in common alum belongs 

 accordingly to the series § XXIII. 



" C. But when, in the decomposition of the first neutral 

 compound, where muriatic acid is the determining element with 

 sulphate of magnesia, the amount of the vitriolic acid is 1394, 

 it is so in all subsequent possible decompositions which the 

 neutral compounds of the other actual and possible elements 

 of the series § XX 1 1, make with the sulphate of magnesia, 

 let these decompositions be positive or negative. (Pure 

 Stoech. Theor. 3, corolL 3.) The quantity, then, of real 

 and possible elements which belong to 1000 parts of muriatic 

 acid belong to 1394 of vitriolic, and the following proportions 

 are obtained for the compounds where the vitriolic acid be- 

 comes at rest with the real and possible elements (Pure 

 Stoech. Theor. 1, corolL 1), all of which obtained by expe- 

 riment except the common alum are neutral. 



