194 JOTTINGS OF A GENTLEMAN GARDENER 



into a dish ; put the dish into an oven and gradually 

 evaporate until there is no water left. Is there any solid 

 matter visible in the dish ? Perhaps not. Then the soil 

 is poor. Perhaps there is a little ? Then the soil is good. 

 But if there is much of it, then the soil is too rich. An 

 authority has said that " a soil containing more than a 

 twentieth part of its weight of soluble matter is too rich 

 for plant life." It is most unusual to get so much as a 

 twentieth part of soluble matter, but in such a case the 

 soil can be greatly improved by adding to it some very 

 poor loam. 



So now we say that our soil consists of mineral matter 

 partly soluble in water, but mostly insoluble, and of 

 humus. 



We may go a step farther and have our soil analysed by 

 a chemist. And if it is an average sample of loamy soil 

 it will contain about 20-22% of sand (oxide of silicon), 

 and the following ingredients will be present in small 

 quantities : Lime (as carbonate, phosphate, or sulphate 

 of Calcium) ; Magnesia (as silicate, chloride, or carbonate 

 of Magnesium) ; Soda (in the form of salt= chloride of 

 sodium, or a trace of nitrate of sodium) ; Potash (as 

 silicate, or carbonate or a trace of chloride of Potassium) ; 

 Sulphur (in the form of sulphates of various kinds such as 

 sulphate of Calcium) ; Alumina (as double silicate of 

 Aluminium and Potassium ordinary clay) ; Chlorine 

 (as Chlorides of various kinds, such as chloride of sodium = 

 salt, double chloride of potassium and magnesium^ 

 Kainit) ; Manganese (as a trace of oxide of manganese) ; 

 Iron (as Ferric Oxide, or as Ferrous or Ferric Sulphate) ; 

 Phosphorus (as Phosphates of various kinds such as 

 Phosphates of Calcium ) ; and Carbon (in the form of 

 carbonates, such as carbonate of Calcium= chalk) . 



Thus it will be seen that the soil contains twelve different 

 elements, Silicon, Calcium, Magnesium, Sodium, Potas- 

 sium, Sulphur, Aluminium, Chlorine, Manganese, Iron, 

 Phosphorus, and Carbon. Sometimes it contains yet 

 others, such as traces of copper, barium, chromium, lead, 



