Researches on the Composition of several 
Japanese Fertilizers. 
BY 
Dr. O. Kellner. 
The nutrients without which green plants cannot at¬ 
tain any normal development and which are taken up from 
the soil through the roots are, besides water, the following : 
nitrogen, potash, lime, magnesia, sesquioxide or protoxide 
of iron, phosphoric acid, and sulphuric acid. Some of these, 
viz. magnesia, iron compounds, sulphuric acid, and mostly 
also lime are so copiously contained in all ordinary soils 
that even continual cropping without any artificial addition 
of them to the fields does not impair the fertility of the lat¬ 
ter. Nitrogen, phosphoric acid, and potash, however, general¬ 
ly exist in soils in relatively small proportions insufficient to 
cover the need of cultivated plants, and are moreover with¬ 
drawn from the fields in the form of crops to such an ex¬ 
tent as to diminish considerably the crop-feeding power of 
the soil. Hence arises the necessity of supplying the latter 
from time to time with these three nutrients in the form 
of manures, otherwise the fertile condition of the soil would 
not be maintained or improved. 
All manures that contain one or more of the three nu¬ 
trients just mentioned are called direct fertilizers, because 
they serve to directly feed the crops. Another group, 
called indirect fertilizers, to, which belong lime, gipsum, 
common salt, etc., indirectly increase the produce, either 
by dissolving and distributing those nutrients which already 
exist in the soil, or by improving the physical conditions of 
the land, or by paralyzing certain injurious properties of 
