"Getting nitrogen from the air, is it not?"

"No, no. That explains it. Getting nitrogen from the air is called
nitrogen fixation. This action is carried on by the nitrogen-fixing
bacteria, such as the clover bacteria, the soy bean bacteria, the
alfalfa bacteria, which, by the way, are evidently the same as the
bacteria of sweet clover, or mellilotus. Then we also have the
cowpea bacteria, and these seem to be the same as the bacteria of
the wild partridge pea, a kind of sensitive plant with yellow
flowers, and a tiny goblet standing upright at the base of each
compound leaf,--the plant called Cassia Chamaecrista by the
botanist."

"Nitrification is an altogether--"

"Well, I declare! Excuse me, Sir, but that's Charlie calling the
cows. Scotts, I don't see where the time has gone! You'll excuse me,
Sir, but I must look after separating the cream. You will greatly
oblige me, Mr. Johnston, if you will have dinner with us and share
our home to-night. In addition to the pleasure of your company, I
confess that I am mightily interested in this subject; and I would
like especially to get a clear understanding of that nitrification
process, and we've not had time to discuss the potash and
'phosphoric acid,' which I know cost some of our farmers a good part
of all they get for their crops, and still their lands are as poor
as ever."

"I appreciate very much your kind invitation, Mr. Thornton. I came
to you for correct information regarding the agricultural conditions
here, and you were very kind and indulgent to answer my blunt