; but, from the standpoint of
an estimate of the practical openings for agriculture improvements in
the near future, it greatly dwarfs the prospect of any epoch-making
change actually founded upon the principle of the rotation of crops.
It is, indeed, conceivable that fresh light on the life habits of the
minute organisms of the soil may lead to practical results quite new;
but hardly any such light is yet within the inventor's field of
vision.

This view of the limited prospects of practical microbiology for the
fixing of nitrogen in plant-food was corroborated by Sir William
Crookes in the Presidential Address already cited. He said that
"practice has for a very long time been ahead of science in respect of
this department of husbandry". For ages what is known as the four
course rotation had been practised, the crops following one another in
this order--turnips, barley, clover and wheat--a sequence which was
popular more than two thousand years ago. His summing up of the
position was to the effect that "our present knowledge leads to the
conclusion that the much more frequent growth of clover on the same
land, even with successful microbe-seeding and proper mineral
supplies, would be attended with uncertainties and difficulties,
because the land soon becomes what is called clover-sick, and turns
barren".

In regard to any practical application of microbe-seeding, the farmers
of the United Kingdom at the end of the nineteenth century had not, in
the opinion of this eminent chemist, reached even the experimental
stage, although on the Continent there had been some extension of
microbe cultivation. To this it may fairly be added that some of the
attention attracted to the subject on the Continent has been due to
the natural tendency of the German mind to discover fine differences
between things which are not radically distinct. Under the title of
"microbe-cultivation" the long-familiar practice of the rotation of
crops may to some continental enthusiasts seem to be quite an
innovation!

In the electrical manures-factory the operations will be simply an
enlargement of laboratory experiments which have been familiar to the
chemist for many years. Moist air, kept damp by steam, is traversed by
strong electric sparks from an induction coil inside of a bottle or
other liquor-tight receiver, and in a short time it is found that in
the bottom of this receptacle a liquid has accumulated which, on being
tested, proves to be