rs.=--Before taking leave of the disorders of the nervous
system, I must briefly mention the Nightmare, or Night Terrors of
children, which often cause a degree of alarm quite out of proportion to
their real importance.

It happens sometimes that a child who has gone to bed apparently well,
and who has slept soundly for a short time, awakes suddenly with a sharp
and piercing cry. The child will be found sitting up in bed, crying out
as if in an agony of fear, 'Oh dear! Oh dear! take it away! father!
mother!' while terror is depicted on its countenance, and it does not
recognise its parents, who, alarmed by the shrieks, have come into its
room, but seems wholly occupied by the fearful impression that has
roused it from sleep. By degrees consciousness returns; the child now
clings to its mother or its nurse, sometimes wants to be taken up and
carried about the room, and by degrees, sometimes in ten minutes,
sometimes in half-an-hour, it grows quiet and falls asleep; and then
usually the rest of the night is passed undisturbed, though sometimes a
second or even a third attack may occur before daybreak.

Seizures of this kind may come on in a great variety of circumstances,
and may either happen only two or three times, or may continue to recur
at intervals for several weeks. The great point, however, to bear in
mind is that they depend invariably on some disorder of the stomach or
bowels, and are never an evidence of the commencement of real disease of
the brain.

FOOTNOTES:

[11] Reports of the Registrar-General, as quoted at p. 30 of my
_Lectures on Diseases of Children_. The actual numbers are 9,350 under
five years old, out of a total of 16,258.

[12] Figures deduced from the 44th Report of the Registrar-General.

[13] Before I called attention to this form of headache in the last
edition of my lectures, it had already been noticed without my
knowledge, by a friend of mine, Dr. Blache, of Paris, in a very valuable
essay on the headaches which occur during the period of growth.

CHAPTER VII.

THE DISORDERS AND DISEASES OF THE CHEST.

In speaking of the ailments which occur during the first month after
birth, I have already noticed the peculiarities of breathing in early
infancy, and the difficulties that sometimes attend the complete filling
of the air-cells of the lungs, and the readiness with which when once
filled they become emptied of air and collapse.

On this ground it is therefore needless fo