232 SOILS, MANURES, &c. 
~n~~nr■ mu m — i n■ ■■■! .—— ——11 ■ mmmmmmmmmm m mmmmammKmgm mmmmmm m mmmwmmmmmmma mmKmmmBmm tcaammmmmu n—ffl| 
abound in any great degree, render the 
foil barren and unprodu&ive. 
Salts are generally allowed to be the 
grand fertilizers of earth ; therefore the 
foil is denominated rich, where they are 
of a proper quality and abound, and 
poor when they are abfent. 
There are two families, or genera, of 
falts, the one alkaline, and the other 
acid, each of which are divided into 
their refpe&ive fpecies, according to their 
fubordinate powers. 
The ftroncrefl acid falts are, 
O y 
ift. Vitriolic acid. 
2d, Nitrous acid. 
qd. Muriatic acid. 
O 
The ftrongeft alkaline falts are, 
ift. Fixed vegetable alkali. 
2d. Cauftic calcareous earth. 
3d. Caullic volatile alkali. 
In 
