n the cure of illness. Dietetics, whether for the
victims of gout, pellagra, fever, tuberculosis, or diabetes, is of
primary importance; lithia salts, caffeine, and creosote are useless
in comparison. The modern tendency is to reject these poisonous
remedies altogether, and to substitute the natural remedies of rest,
medical gymnastics, hydropathic treatment, and, above all, climatic
treatment. Psychiatry and neuropathology have introduced the treatment
of work: that is, a course of orderly intelligent activity, to give
occupation to individuals who begin to show signs of mental failure.
By degrees, as progress is made in this direction, the conception of
"natural healing" will triumph--the ever clearer conception, that is
to say, of the forces which sustain life.

It is only Nature which can do everything, and if the doctor is to
become useful he must follow in her footsteps and serve her with
increasing fidelity.

It is natural that investigation should lead to attempts at
interpreting these forces upon which health depends, and these studies
of "immunity" have been the most brilliant, widely diffused and
scientific of all medical studies.

When Metchnikoff believed he had discovered that the leucocytes in the
blood absorb and digest microbes and thus save man from infection, it
seemed as if a ray of clear and simple light had illuminated all the
mystery. But no sooner was his theory promulgated than it was
demolished by the successive studies in which it was subjected to a
destructive criticism, because the leucocytes are not always able to
absorb living microbes; certain "conditions" of the organism are
requisite in order that they may have this power, and so the knotty
point was merely shifted. Moreover, it is not the actual microbes
which cause disease, but their toxines. Thus the theories of toxines
seemed to be the true guide for researches; but then we entered into a
sea of complications, and it is obvious that only "aspects" and
"attributes" of immunity are accessible to us, but that the substance,
the last word, underlying all those aspects which research has
revealed is: mystery.

For this reason, there is silence to-day as to questions of immunity;
that which was once familiar as a popular idea remains among the
obscure studies which not even the students of the university should
approach.

Nevertheless, it is "impossible" that the medical science founded upon
natural forces should develop, unless th