cases, however, otherwise characteristic, these more severe
manifestations are absent or but little apparent. Recovery is usually
rapid and complete. The child asks for food, which is retained. A
fatal ending is very rare, though not unknown. The frequency of
attacks is very various. Sometimes months or even years may elapse
between successive seizures; in other cases a fortnightly or monthly
rhythm establishes itself.

It is clear that both the frequency and the severity of the attacks
are much influenced by the general state of the child's health. Like
migraine, cyclic vomiting appears to be a symptom of nervous
exhaustion. It affects, for the most part, children who are
intellectually alert, impressionable, and forward for their age, and
who, when well, throw themselves into work or play with a great
expenditure of nervous energy. Often their physical development is
unsatisfactory, and we must set ourselves to correct this as the first
step in prevention. It is highly important that children suffering in
this way should have free opportunities for exercise in the open
country, and that all the excretory organs--the skin, kidneys, and
bowels--should be acting freely and efficiently. The child should live
a life of ordered routine. Sleep should be sound and sufficient in
amount. The diet must not exceed the strict physiological needs. Many
of these children appear to have a lowered tolerance for fats of all
sorts, and it may be necessary to limit strictly the consumption of
milk, cream, butter, and so forth. A daily administration of a small
dose of alkali by the mouth is credited with preventing attacks. In
the present connection, however, we shall not do wrong to emphasise
the part played by the nervous system in the production of the
attacks. In all cases of cyclic vomiting it should be our endeavour to
recognise and remove the elements in the daily life of the child which