HISTORT OF THE ATOMIC THEOKY. 197 



" Now let us suppose that these alkaline earths, which are 

 partly real, partly possible, and designated by the above num- 

 bers, entered with muriatic acid into such neutral combina- 

 tions as would decompose with a neutral compound out of the 

 series § XXIII., such as the magnesia salt, by double affinity 

 either positive or negative (see Pure Stoechiometry. Theor. 

 3, coroll. 3. Introd. definition 16), then only that neutral 

 compound is excepted which the muriatic acid makes with the 

 alkaline element of the neutral salt which we have chosen in the 

 series XXI II., or the combination which is also taken with 

 the magnesia salt. But according to experiment 6, coroll. 

 2, in the Pure Stoechiometry, in the decomposition by double 

 affinity, out of three proportions the fourth may be deter- 

 mined. Let us suppose, then, that all the mentioned actual 

 and possible neutral combinations, magnesia salt excepted, 

 decompose with sulphate of magnesia (bitter salt) either 

 positively or negatively, so that each constituent is placed in 

 a state of rest (Pure Stcech. Theor. 1, coroll. 1); then we 

 may find how many measures of each of the real and possible 

 elements are wanted for 1000 parts of the vitriolic acid mea- 

 sures. (Pure Stoech. Introd. def. 14.) 



" B. The first neutral compound in the series, § XXII., is 

 an actual one, namely, alum salt, where 734 parts of alumina 

 stand in neutrality with 1000 parts of muriatic acid. If this 

 neutral or middle salt decomposes with sulphate of magnesia 

 by double affinity, then 858^ parts of magnesia must be con- 

 tained in the sulphate of magnesia, because the proportionate 

 quantity in the magnesia salt is as 1000:858, or rather 

 1000: 858^. § XXII. Now the proportionate quantity 

 in the sulphate of magnesia is 1000:616 (§ XIX., XXIII.) 

 and 616 : 1000=858^: 1,394 ; that is, if 616 parts of mag- 

 nesia insist on rest with 1000 parts of vitriolic acid, the same 

 must occur between 858^ parts of the first and 1394 parts of 

 the latter; therefore when alumina salt and magnesia salt 

 decompose, 1000 parts of muriatic acid dissolve with 868 J 



