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the air, either directly or indirectly, by means of minute organisms 
now generally termed microbes. These microbes can be communi- 
rated by direct inoculation from one plant to another that has been 
previously free from them. .Experiments are in progress as to the 
possibility of cultivating these microbes artificially, and when this 
has been accomplished successfully it will mark a great step toward 
the solution of the question as to the plant’s method of obtaining 
nitrogen, and not only that, but a great step toward success in agri- 
culture, since every one will be able to inoculate his own plants, and 
thus immensely stimulate the yield of crops. 
T. Leone has shown that a great number of germs obtain their 
nitrogen more easily by decomposing the nitrates, and only when 
these salts are used up do they begin to nitrify the ammoniacal com- 
pounds, and after that possibly attack the free nitrogen of the air. 
He has also shown that these take the nitrogen as a gas from the 
nitric acid in the nitrates and do not convert it into ammonia. (Agr. 
ser. Vol, V5 p. 62.) 
Leone also shows that the phenomena of nitrification and denitri- 
fication occur alternately according to the relative amount of nutri- 
ment and number of bacteria present in the water. The manuring of 
soul, therefore, gives rise to a cycle of phenomena, nitrification being 
first arrested and the nitrates and nitrites reduced until a maximum 
formation of ammonia is attained, when nitrification again com- 
mences. The destruction of the nitrates and nitrites in the soil is 
complete or partial according as the supply of manure is abundant 
or otherwise. (Agr. Sci., Vol. V, p. 107.) 
The experiments made in Europe by Boussingault, Hellriegel, and 
others as to the method by which plants obtain the nitrogen from the 
atmosphere have been repeated and extended by C. D. Woods, of the 
Storrs School Agricultural Experiment Station. His results are 
summarized as follows: 
(1) Peas, alfalfa, serradella, lupine, probably clover, and appar- 
ently all leguminous plants, have the power of acquiring large quanti- 
ties of nitrogen directly from the air during their growth. ‘There 
is no doubt that the free nitrogen of the air is thus acquired by these 
plants. This acquisition has something to do with the tubercles on 
the roots of these plants, but the details of the process are still to be 
solved. The cereals, oats, etc., with which experiments have been 
brought to completion, do not have this power of acquiring nitrogen 
from the air, nor do they have such tubercles as are formed on the roots 
of the legumes. They get their nitrogen from the nitrates or nitrogen- 
ous fertilizers. The tubercles on the roots of the legumes may be formed 
either after or entirely without the addition of solutions or infusions 
containing micro-organisms, and a plausible supposition is that when 
such infusions are not furnished the spores of the organisms were 
