On the Chemical Propei'ties of Soils. 
Ill 
1000 grains of the latter, as we have seen, absorbed ''JIDS grains 
of ammonia. The difference between 'OlDB grains and '882 
grains is "0373 grains, and represents the quantity of ammonia 
neutralised by the organic matters contained in 1000 grains of 
the soil. This difference is very small, but it nevertheless con- 
firms my supposition, and at the same time affords a good proof 
of the delicacy of the method employed in theSe experiments. 
Second Experiment, on Fertile Loamy Soil. 
Equal parts of surface and subsoil were mixed together. The 
surface soil is a friable sandy loam ; the subsoil is stiffer, con- 
taining less sand and more clav. 
The mechanical analysis of this soil and its subsoil gave : — 
Surface-soil. 
Subsoil. 
Sand .. .. 
76-16 
55-15 
Clay 
18-09 
41-79 
1-37 
•47 
4-38 
2-59 
100-00 
100-00 
Submitted to detailed chemical analysis, the soil and subsoil 
were found to contain in 100 parts : — 
Surface-soU. Subsoil. 
Organic matter and water of combination .. 4-38 2-59 
Alumina .. ..■ .. .. 2-15 5-39 
Oxide of iron 3-15 7-16 
Lime .. -77 -26 
Magnesia -13 1-22 
Potash -49 -88 
Soda -13 -28 
Phosphoric acid -12 -19 
Chlorine .• .i- ..■ .. .. trace, trace. 
Sulphuric acid -06 -02 
Carbonic acid .. .i- .. .. .. '31 1-79 
Insoluble silicate and sand .. .. 88-31 80*24 
Consisting of : — ■ 
Silicic acid 85-11 62-61 
Alumina 2-36 14-55 
Lime -85 
Magnesia -50 "23 
Potash -25 1-77 
Soda -09 -21 
100-00 100-00 
* Containing nitrogen -182 -09 
Equal to ammonia -220 -11 
3500 grains of this soil and subsoil were mixed with 14,000 
grains of the above ammonia solution, and, after repeated shak- 
ings in a well-stoppered bottle, allowed to settle for three days, 
by which time the liquid became perfectly clear. The greater 
