i,5i 
of elective Attractions. 
lime, the fluate of barita cannot decompose the nitrate of lime, 
since the previous attractions of these two salts are respec- 
tively greater, than the divellent attractions of the nitrate of 
barita and the fluate of lime. Probably, therefore, we ought 
to place the fluoric acid below the nitric under barita ; and 
we may suppose, that when the fluoric acid has appeared to 
form a precipitate with the nitrate of barita, there has been 
some fallacy in the experiment. 
The third proposition is somewhat less obvious, but per- 
haps of greater utility : there must be a continued sequence 
in the order of double elective attractions ; that is, between 
any two acids, we may place the different bases in such an 
order, that any two salts, resulting from their union, shall 
always decompose each other, unless each acid be united to 
the base nearest to it : for example, sulfuric acid, barita, po- 
tass, soda, ammonia, strontia, magnesia, glycina, alumina, zir- 
conia, lime, phosphoric acid. The sulfate of potass decomposes 
the phosphate of barita, because the difference of the attrac- 
tions of barita for the sulfuric and phosphoric acids is greater 
than the difference of the similar attractions of potass ; and in 
the same manner the difference of the attractions of potass is 
greater than that of the attractions of soda ; consequently the 
difference of the attractions of barita must be much greater 
than that of the attractions of soda, and the sulfate of soda 
must decompose the phosphate of barita : and in the same 
manner it may be shown, that each base must preserve its 
relations of priority or posteriority to every other in the series. 
It is also obvious that, for similar reasons, the acids may be 
arranged in a continued sequence between the different bases; 
and when all the decompositions of a certain number of salts 
