elation between the volumes of the
plasma and corpuscles can be read off. No microscopical alterations in
the corpuscles are to be observed.

Though this procedure seems very difficult of execution, it is
nevertheless the only one, which has really advanced clinical pathology.
The results of Koeppe--not as yet very numerous--give the total volume
of the red corpuscles as 51.1-54.8%, an average of 52.6%.

M. and L. Bleibtreu have endeavoured indirectly to ascertain the
relation of the volume of the corpuscles to that of the plasma.
Mixtures of blood with physiological saline solution in various
proportions are made, in each the amount of nitrogen in the fluid which
is left after the corpuscles have settled is estimated. With the aid of
quantities so obtained they calculate mathematically the volume of the
serum and corpuscles respectively. Apart from the fact that a dilution
with salt solution is also here involved, this method is too complicated
and requires amounts of blood too large for clinical purposes. Th.
Pfeiffer has tried to introduce it clinically in suitable cases, but has
not so far succeeded in obtaining definite results. That, however, the
relations between the relative volume of the red corpuscles and quantity
of haemoglobin are by no means constant, is well shewn by conditions (for
example the acute anaemias) in which an "acute swelling" of the
individual red discs occurs (M. Herz), but without a corresponding
increase in haemoglobin. The same conclusion results from recent
observations of v. Limbeck, that in catarrhal jaundice a considerable
increase of volume of the red blood corpuscles comes to pass under the
influence of the salts of the bile acids.

As we have several times insisted, the quantity of haemoglobin affords
the most important measure of the severity of an anaemic condition. Those
methods which neither directly nor indirectly give an indication of the
amount of haemoglobin are only so far of interest that they possibly
afford an elucidation of the special pathogenesis of blood diseases in
particular cases. To these belong the ESTIMATION OF THE ALKALINITY OF
THE BLOOD, which in spite of extended observations has not yet obtained
importance in the pathology of the blood.

A value to which perhaps attention will be more directed than it has up
to the present time by clinicians is the RATE OF COAGULATION OF THE
BLOOD, for which comparative results may be obtained by Wright's handy
apparatu