On Pariiuj and Burning. 347 



ever, of primary utility to the occupier of land. The want of 

 a clear perception of a scientific truth, and its bearing upon the 

 farm routine, as followed in tliis or that locality, is a fertile 

 source of endless disputes. In order fully to appreciate the 

 objections of those who, I think, attach, g-enerally speaking', too 

 great an importance to the organic matters in the soil, it appears 

 to me desirable to allude briefly to the functions of humus, i. e. 

 organic matters in a state of progressing decomposition. I 

 would, therefore, observe : — 



1. Humus is an excellent absorber of moisture, and for this 

 reason of special use in sandy and other naturally dry soils. In 

 illustration of tiiis property, the following partial analyses of two 

 soils may find here an appropriate place. Both soils are from 

 Buckinghamshire. Before proceeding with their analysis, I 

 kept them in a heated room, in a powdered state, until they 

 were perfectly airdry, neither gaining nor losing water when 

 weighed from day to day. In this state they were analysed, and 

 the following results obtained : — 



Xo. T. No. II. 



Moisture 4-70 22-35 



Organic matter and water of combination .. 5"9S 22"01 



Oxides of iron and ahimina lO'ol 16"02 



Carbonate of lime l-,32 '95 



,, magnesia '85 •43 



Phosphoric and sulphuric acid trace trace 



Alkalies, chlorine, and loss '47 '56 



Insoluble silicious matter (chiefly sand) .. 76*17 37'68 



100-00 100-00 



No. I. was a soil in wheat. No. II. soil in permanent pasture. 



The wheat soil, it will be seen, contained nearly 6 per cent, 

 of organic matter, and retained, in a moderately-dry atmosphere, 

 about 5 per cent, of moistui-e, which was only driven off at the tem- 

 perature of boiling water. The pasture-land contained 22 per 

 cent, of organic matter, and, under the same circumstances in 

 Avhich No. I. retained only 5 per cent, of moisture, was capable 

 of retaining no less than 22 per cent. 



2. Humus not only absorbs and retains moisture from the 

 atmosphere, but also ammonia ; and this it does in virtue of its 

 porosity, no less than in virtue of the chemical aflfinity which 

 the humic and ulmic acids found in humus possess for ammonia. 



3. The organic remains in soils contain nitrogen, and, on 

 gradual decomposition, give rise to the formation of ammonia, 

 which at once is fixed by the humic acids generated at the same 

 time during the decomposition of the organic matters of the 

 soil. 



4. Organic matters, in order to be decomposed, must be 



