the Attractive Powers of Mineral Acids, 4 3 
cm pole cl the common hilt; and this explanation is confirmed 
by the fmall proportion of Glauber’s fait, which is laid to be 
obtained by this procefs ; for from 30 lbs. of common hilt and 
16 lbs. of allum only, 15 lbs. of Glauber’s fait were pro- 
duced ; whereas, if the whole of the allum were decompofed, 
there Ihould be formed, according to my computation of the 
proportion of acid in different halts, 29 1 lbs., and, according 
to Mr. bf.rgman’s, 22 lbs. of Glauber’s fait. 
Behdes tliefe powers there exilfs another which neutral halts 
poflels, of uniting to certain hub dances, without buffering any, 
or but a very fmall, decompolition ; and thus forming triple 
hilts, and lometimes quadruple. This often caufes anomalies, 
and has not as yet been fufficiently invedigated *. Volatile 
alkalies in particular poffefs this power ; and hence, perhaps, 
arifes the difference between Mr. bergman’s table and mine, 
with regard to them and magneda ; for though, when perfectly 
caudic, they do not perfectly precipitate magneda from Enfom 
fait, it is becaufe they combine with this fait and form a triple 
fait. 
According to my table, the three mineral acids have the 
fame affinity to vegetable dxed alkalies, which will undoubtedly 
appear extraordinary to many, as it is well known, that the 
vitriolic acid decompofes both nitre and halt of lylvius ; but it 
fliould be remarked, that tartar vitriolate is aifo decompofed by 
the nitrous and marine acids, as Mr. baume, marGraaf, 
and bergman, have found ; and nitre is decompofed by the 
marine acid, as Mr. cor net te has fhewn at large in the Me- 
moirs of Paris for 1778; and not only thefe falts, but alfo 
Glauber’s fait and vitriolic ammoniac, are decompofed by the 
* In my next paper I fliall examine fome exceptions arifing from this fource. 
G 1 ' nitrous 
