108 



THE SOIL. 



To represent different soils, containing Vcarious propor- 

 tions of nutritive substances, three mixtures were made 

 of saturated and ordinary turf-powder : — 



1 mixture contained 1 vol. of saturated turf-powder, 



2 ,, 1 „ „ and 1 vol. of diy turf-powder 



These mixtures represented different kinds of earth, in 

 each vokuiie of which the third contamed one-fourth, the 

 second one-half the quantity of the nutritive substances 

 present in the first. 



The pure turf contained 2-5 per cent, of nitrogen, and 

 100 grammes yielded 4*4 grammes of ash, which, upon 

 analysis, were found to contain 0T15 gramme of potash, 

 0-0576 gramme of phosphoric acid, besides lime, sesqui- 

 oxide of iron, sihcic acid, magnesia, sulphuric acid, and 

 soda. (See more fully in Appendix E.) 



With each of these mixtures a pot was filled, each pot 

 holding 8:^ litres (2592 grammes, = 39917 grs.) ; a 

 fourth pot, of similar size, contained dry turf-powder. 



Taking into consideration the amount of ash in 

 ordinary turf, the four pots severally contained the 

 following quantities of nutritive substances : — 



Nitrogen . 



Potash . 



Phosphoric 



acid 



1st Pot 



with common 



turf 



Grams. Grains 



71- =1093-5 



3-18 -= 49-0 



2nd Pot 



quarter satm-ated 



turf 



Grams. Grains 

 2-60 =40-0 

 3-075 = 47-4 



0-83 =12-8 



3rd Pot 



hall saturated 



tui-f 



Grams. Grains 

 4-32 = 66-5 

 6-15 = 94-7 



1-75 = 27-0 



4th Pot 

 fully satiu-ated 



Grams. Grains 

 8-65 = 133-2 

 12-30 = 189-5 



3-49= 53-8 



The figures showing the quantities of nitrogen, potash, 

 and phosphoric acid, express the amount of nitrogen in 

 the dry turf (in the first pot), and the amount of potash 

 and phosphoric acid in its ash. For the other pots, the 

 figures express the quantity of nutritive substances which 

 had been added. 



