satiety
produced by an often-repeated dish, and the gratification caused by one
long a stranger to the palate, are _not_ meaningless, as people
carelessly assume; but they are the incentives to a wholesome diversity
of diet. It is a fact, established by numerous experiments, that there
is scarcely any one food, however good, which supplies in due
proportions or right forms all the elements required for carrying on the
vital processes in a normal manner: whence it follows that frequent
change of food is desirable to balance the supplies of all the elements.
It is a further fact, known to physiologists, that the enjoyment given
by a much-liked food is a nervous stimulus, which, by increasing the
action of the heart and so propelling the blood with increased vigour,
aids in the subsequent digestion. And these truths are in harmony with
the maxims of modern cattle-feeding, which dictate a rotation of diet.

Not only, however, is periodic change of food very desirable; but, for
the same reasons, it is very desirable that a mixture of food should be
taken at each meal. The better balance of ingredients, and the greater
nervous stimulation, are advantages which hold here as before. If facts
are asked for, we may name as one, the comparative ease with which the
stomach disposes of a French dinner, enormous in quantity but extremely
varied in materials. Few will contend that an equal weight of one kind
of food, however well cooked, could be digested with as much facility.
If any desire further facts, they may find them in every modern book on
the management of animals. Animals thrive best when each meal is made up
of several things. The experiments of Goss and Stark "afford the most
decisive proof of the advantage, or rather the necessity, of a mixture
of substances, in order to produce the compound which is the best
adapted for the action of the stomach."[3]

Should any object, as probably many will, that a rotating dietary for
children, and one which also requires a mixture of food at each meal,
would entail too much trouble; we reply, that no trouble is thought too
great which conduces to the mental development of children, and that for
their future welfare, good bodily development is of still higher
importance. Moreover, it seems alike sad and strange that a trouble
which is cheerfully taken in the fattening of pigs, should be thought
too great in the rearing of children.

One more paragraph, with the view of warning those