SOILS, MANURES, &c. 247 
Vitriolic acid is found in the earth, 
united with various metallic and fulphu- 
reous fubftances. 
Muriatic acid is found in the earth, 
in mineral waters, the fea, See. it is the 
weakeft of the mineral, but Itronger than 
any vegetable acid: it is poifonous to 
plants, as are all mineral or metallic 
fubftances whatfoever. 
Sea fait is by fome people ufed as a 
manure; it certainly contains fome foflil 
or mineral alkali, but it abounds with 
muriatic acid, and therefore cannot, by 
any means, be recommended as a fafe 
and eligible manure^ which the following 
experiment will tend in fome meafure to 
demonftrate, 
A quantity of fea fait, in folutian, 
was applied to part of a palture field; 
the foil became, in confequence, barren 
and unproductive for more than twenty 
years ; 
