ct. "He
prepared vessels and solutions, carefully purified from organic matter,
and these solutions he sowed with the nitrifying organism. Finding that
under these conditions the nitrifying organism increased enormously and
displayed its full vigour, he proceeded further to determine the amount
of carbonaceous organic matter formed in solutions after the
introduction of the organism. By making the nitrification intensive, he
was able to obtain considerable quantities of carbon from the nitrified
solutions by the process of wet combustion. In his third memoir he
publishes figures which apparently show a close relation between the
amount of nitrogen oxidised, and the amount of carbon assimilated; the
ratio is about 35:1."--See Bulletin of U.S. Department of Agriculture,
No. 8, containing Lectures on Rothamsted Experiments by R. Warington,
F.R.S., p. 50.

NOTE III. (p. 170).

The oxidising power of the micro-organisms of soil is not confined to
the oxidation of ammonia or of organic matter. Muentz has shown that soil
is capable of oxidising iodides to hypo-iodides and iodates, and
bromides to hypo-bromides and bromates. This is a very important result,
and seems to indicate that nitrification is part of a general oxidising
action, and that we must not assume that nitrites or nitrates are
produced because they are in themselves of advantage to the organism.

NOTE IV. (p. 172).

"When urine in different degrees of dilution was treated with soil, 1
gram of soil being added to 100 c.c. of diluted urine, nitrification
commenced in the 1-per-cent solution in 11 days, in the 5-per-cent
solution in 20 days, in the 10-per-cent solution in 62 days, in the
12-per-cent solution in 90 days. The alkalinity of the last-named
solution when nitrification commenced was equal to 447 mgs. of ammonia
per litre. A solution with an alkalinity of 500 mgs. of ammonia per
litre is apparently unnitrifiable."--American Department of Agriculture
Bulletin, Warington's Lectures on Rothamsted Experiments, p. 51.

NOTE V. (p. 171).

Professor P. F. Frankland in his experiments used the following
solutions:--

grms.
NH_{4}Cl .5 }
H_{3}PO_{4} .1 }
MgSO_{4} .02 > In 1000 c.c. of distilled water.
CaCl_{2} .01 }
CaCO_{3} 5.00 }

NOTE VI. (p. 185).

Experiment by Boussingault on Rate of Nitrification.

Percentage of Nitrate
1857. of Potash. = lb. per acre.
Augu