ur are. Then sulphur, phosphorous, silica (sand,)
and chlorine (salt). I shall soon have rich land and big crops."

Charley, who has recently come home from college, where he has been
studying chemistry, looked at the Deacon, and was evidently puzzled to
understand him. Turning to the Doctor, Charley asked modestly if what
the Doctor had said in regard to the composition of plant food could not
be said of the composition of all our animals and plants.

"Certainly," replied the Doctor, "all our agricultural plants and all
our animals, man included, are composed of these twelve elements,
oxygen, hydrogen, carbon, and nitrogen; phosphorus, sulphur, silica,
chlorine, potash, soda, magnesia, and lime."

Charley said something about lime, potash, and soda, not being
"elements;" and something about silica and chlorine not being found in
animals.

"Yes," said I, "and he has left out _iron_, which is an important
constituent of all our farm crops and animals." Neither the Doctor nor
the Deacon heard our remarks. The Deacon, who loves an argument,
exclaimed: "I thought I knew all about it. You told us that manure was
the food of plants, and that the food of plants was composed of the
above twelve elements; and now you tell us that man and beast, fruit and
flower, grain and grass, root, stem, and branch, all are composed or
made up of these same dozen elements. If I ask you what bread is made
of, you say it is composed of the dozen elements aforesaid. If I ask
what wheat-straw is made of, you answer, the _dozen_. If I ask what a
thistle is made of, you say the dozen. There are a good many milk-weeds
in my strawberry patch, and I am glad to know that the milk-weed and the
strawberry are both composed of the same dozen elements. Manure is the
food of plants, and the food of plants is composed of the above dozen
elements, and every plant and animal that we eat is also composed of
these same dozen elements, and so I suppose there is no difference
between an onion and an omelet, or between bread and milk, or between
mangel-wurzel and manure."

"The difference," replied the Doctor, "is one of proportion. Mangels and
manure are both composed of the same elements. In fact, mangels make
good manure, and good manure makes good mangels."

The Deacon and the Doctor sat down to a game of backgammon, and Charley
and I continued the conversation more seriously.

CHAPTER III.

SOMETHING ABOUT PLANT-FOOD.

"The Doctor is in the