Io GARDENING FOR ALL. 
(1) The chemical effects of the soil depend mainly 
upon certain soluble minerals contained therein, especially 
the Chloride of Sodium (common Salt) and Carbonate 
of Lime. Soda and Lime attract certain plants to which 
they are necessary, but they are obnoxious to others 
which only find refuge in soils free from them. Silica on 
land seems to be mainly neutral chemically. Potash is 
indispensable to plants, but it does not appear to exercise 
any appreciable influence in their geographical distribution. 
Magnesia and Iron enter into the composition, in a small 
degree, of most plants, though neither appear to exert any 
special influence in their geographical distribution. Nitrogen 
and Phosphorus are absolutely essential to vegetable life, 
and increase the vigour of plants grown on all soils. 
As a knowledge of soils and their chemical nature is of 
great value to the cultivator, I here give a list of soils, with 
their chemical analyses, which will serve as a guide to those 
possessing similar soil :— 
Certain marls contain 
from 3°4 to 25°38 per cent. of Alumina and Iron Oxide. 
7°69 to 66°67 i Carbonate of Lime. 
1:82 to 2°91 da Phosphoric Acid. 
068 to 510 ii Carbonate of Magnesia. 
Some clays contain 
from 48:99 to 73°82 per cent. of Silica 
103 to 32°11 9 Alumina. 
O12 to 262 Se Lime. 
Ol td 9°33 es Potash. 
o4I to 3:0 e Magnesia. 
0°44 to 2.40 fs Soda. 
o32to 417 si Iron Protoxide. 
There are limestones which contain 
from 44°6 to 98'4o per cent. of Carbonate of Lime. 
0°08 to 40-2 ” ” Magnesia. 
IO to 51°4 vs Silica. 
o42to 82 re Tron and Alumina. 
Different sandstones contain 
from 49°4 to 98:00 per cent. of Silica. 
o25to 32 a Alumina. 
0°35 to 26°5 i‘ Carbonate of Lime. 
0°75 to I6°1 w Magnesia. 
0725 to 3°51 er Iron Protoxide. 
