74 
JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY, 
matter (ash) was found to be 2’7 per cent, in the fresh substance, 
and nearly 12^ per cent, in the material when frilly dried. The 
nitrogen is shown to be about \ per cent, in the fresh fibre, and 
nearly 1 per cent, in the fully dried substance. The Jadoo fibre 
is, therefore, richer in organic matter and in nitrogen than the 
famous leaf-moulds of Eambouillet and Maurepas, France, so 
largely used in the horticultural establishments of that country. 
But while it does not contain so much organic matter or nitrogen 
as the Ghent heath mould, it is richer in mineral constituents. 
The chemical composition thus given pretty clearly shows that 
the reason of the great value of Jadoo fibre rests in the fact 
that the organic nitrogen is readily susceptible of nitrification, 
and so of becoming easily available to vegetation. 
Nitrates in the Soil. 
As soil fertility is of so much importance to the horticul¬ 
turist in the productiveness of the garden, and as the final 
returns may be expected to be directly proportionate to the 
amount of nitrates which it contains, and to the facilities or 
favourable conditions offered for the conversion of organic 
nitrogen into ammonia and nitrates, the subject of nitrification 
in the soil becomes one of intense interest. 
Nitric acid is a compound of nitrogen which represents the 
form of combination in which nitrogen must be in order that 
plants may use it as food. The organic nitrogen of the soil, as 
well as that contained in such fertilising materials as leaf mould, 
peat mould, stable and farmyard manure, blood, fish, rape cake, 
vegetable and animal refuse, &c., is not in a condition to serve 
as plant-food. To become available it must be converted into 
ammonia and then into nitric acid. This change is accomplished 
by certain living organisms, known as bacteria, which exist in 
all fertile soils—the carbon of the humus being at the same 
time oxidised to carbonic acid, whereby heat is developed. The 
different stages of the work are apparently performed by different 
species of bacteria. 
We are told by Professor Warington that the final nitrifica¬ 
tion of ammonia, which is a product of oxidation or decay, is 
performed by two species of bacteria, one of which produces 
nitrites, which the other changes into nitrates, the latter being 
the form in which plants take up most of their nitrogenous food. 
