school says this is due to anæmia of the brain during sleep. Clark traces
the cause to lessened inhibitory powers owing to the higher brain centres
being at rest, while Haig claims to have explained the high incidence at
this hour by the fact that uric acid is present in the system in the
greatest amount at this time.

Some doctors have thought, on the contrary, that _excess_ of blood in the
head was the cause, but results of treatment so directed did not bear out
the sanguine hopes built on the theory.

The fact that convulsions occur in diabetes and alcoholism, suggested that
epilepsy was due to poisons circulating in the blood, and thus irritating
the brain. Every act uses up cell material and leaves waste products,
exactly as the production of steam uses up coal and leaves ashes. Various
waste products have been found in more than normal quantities in the blood
of epileptics, but it is uncertain whether accumulation of waste products
causes the seizure.

A convincing theory must satisfactorily account for all the widely diverse
phenomena seen in epilepsy, and the problem must remain largely a matter of
speculation, until research work has given us a far deeper insight into the
biochemistry of both the brain cells, and the germ-plasm than we have at
present.

* * * * *

CHAPTER V

PREVENTION OF ATTACKS