electricity which the blood current should yield, and the result will be
neuralgia.

It is the magnetic iron in haemoglobin which makes every sort of
nervous function possible, in the cerebral (brain) and in the
sympathetic (intestinal) tracts, and since it is thus made clear that
intellectual activity on the one hand and breathing and digestion and
excretion on the other are dependent on the iron content of the blood,
we must also recognize that, as iron attends every nerve action, the
secretion of urine too takes place under the influence of haemoglobin.
Insofar as haemoglobin hastens the departure of the excrementitious
matter in urine out of the system, there is a daily loss of iron in the
urine. This loss in the form of urohaematin may total four centigrams,
or a hundredth part of our supply.

This loss of iron if not replaced by eating suitable food will soon make
itself felt. In the course of a day the reduction by four centigrams
will diminish the energy of nervous activity about 1440 times the
apparent loss, so that even a four weeks-tropical fever, during which no
meat is eaten, may completely exhaust the strength of an individual.
Moreover, iron conditions bodily warmth as it combines with oxygen in a
higher and a lower degree. In the lungs it is highly oxidized by the
respired oxygen, but in contact with the nerve ends it gives itself only
to a part of the oxygen present, and burns a certain portion of the
lecithin to water, carbonic acid and phosphates, thus creating body
warmth to a considerable extent.

In response to the chemical consumption of lecithin a new oil flows down
the axis cylinders of the nerve fibrils, which are arranged like lamp
wicks. The duration of the flow of this oil is, on the average, about