accumulations. It is sometimes annoying to nervous
persons because of the frequent micturition it makes necessary. I have
discovered that while skimmed milk alone is being taken, uric acid
usually disappears almost entirely from the urine, so that it is
difficult to discover even a trace of this substance; nor does it seem
to return so long as nothing but creamless milk is used. Almost any
large addition of other food, but especially of meat, enables us to find
it again. Creatine and creatinine also seem to lessen in amount, but of
the extent of this change I am not as yet fully informed.

A yet more singular alteration occurs as to the pigments. If after a
fortnight or less of exclusive milk diet we fill with the urine a long
test-tube, and, placing it beside a similar tube of the ordinary urine
of an adult, look down into the two tubes, we shall observe that the
milk urine has a singular greenish tint, which once seen cannot again be
mistaken. If we put some of this urine in a test-tube carefully upon hot
nitric acid, there is noticed none of the usual brown hue of oxidized
pigment at the plane of contact. In fact, it is often difficult to see
where the two fluids meet.

The precise nature of this greenish-yellow pigment has not, I believe,
been made out; but it seems clear that during a diet of milk the
ordinary pigments of the urine disappear or are singularly modified. A
single meal of meat will at once cause their return for a time.

These results have been carefully re-examined at my request by Dr.
Marshall in the Laboratory of the University of Pennsylvania, and his
results and my own have been found to accord; while he has also
discovered that during the use of milk the substances which give rise to
the ordinary faecal odors disappear, and are replaced by others the
nature of which is not as yet fully comprehended. The changes I have
here pointed out are remarkable indications of the vast alterations in
assimilation and in the destruction of tissues which seem to take place
under the influence of this peculiar diet. Some of them may account for
its undoubted value in lithaemic or gouty states; but, at all events,
they point to the need for a more exhaustive study both of this and of
other methods of exclusive diet.

As regards milk, enough has here been said to act as a guide in its
practical use in the class of cases with which we are now concerned; but
I may add that it is sometimes useful, as the case pr