hes can be cured by dieting than
we at one time believed, and underfeeding is a more frequent cause than
overeating.

By an odd _bouleversement_ the one type of headache which we have almost
unanimously in the past attributed to digestive disturbances, the
famous, or, rather, infamous, "sick headache," is now known to have
little or nothing to do with the stomach in its origin. In fact,
incredible as it may seem at first sight, it is the headache that causes
the sickness, not the sickness the headache. Stop the pain of a sick
headache in the early stage, and the sickness will never develop at all.
The vomiting of sick headache is an interesting illustration of vomiting
due to disturbances of the brain and nervous system, technically known
as central vomiting. Another illustration is the vomiting of
seasickness, due solely to dizziness from the gross contradiction
between the testimony of our eyes and of the balancing canals in the
inner ear. The stomach or its contents has no more to do with
seasickness than the water in a pump has with the plunger. Injuries to
the head will bring on severe and uncontrollable vomiting, and the
severer type of fevers is very frequently ushered in by this curious
sign. As to what it means, we are as yet utterly in the dark, for in
none of these conditions does the process do the slightest good, but
simply adds to the discomfort of the situation. It would appear to be a
curious echo of ancestral times, when the animal was pretty much all
stomach, and hence emptying that organ would probably relieve two-thirds
of his discomforts. Whatever the explanation, the fact remains that
whenever our nervous system gets about so panic-stricken, it promptly
begins throwing its cargo overboard, in the blind hope that this may
somehow relieve the situation. The bile that we bring up at the end of
these interesting acrobatic performances and which makes us feel so much
better,--because we have now got the cause of the trouble out of our
system,--is simply due to the prolonged vomiting, which has reversed the
normal current and caused the perfectly healthy bile from our
unoffending liver to pass upward into the stomach, instead of downward
into the bowels.

In another great group of headaches natural poisons or waste-products
are not burned up or got rid of through the body-sewers and pores as
rapidly as they should be; for instance, the familiar headache from
sitting too long in a stuffy room. Your well