A Full Life: The Works of Charlotte Mason

Rest.––Just as important is it that the brain should have due rest; that is, should rest and work alternately. And here two considerations come into play. In the first place, when the brain is actively at work it is treated as is every other organ of the body in the same circumstances; that is to say, a large additional supply of blood is attracted to the head for the nourishment of the organ which is spending its substance in hard work. Now, there is not an indefinite quantity of what we will for the moment call surplus blood in the vessels. The supply is regulated on the principle that only one set of organs shall be excessively active at one time––now the limbs, now the digestive organs, now the brain; and all the blood in the body that can be spared goes to the support of those organs which, for the time being, are in a state of labour.