6 
Journal of the 
(9.) From a consideration of the action of the several chemical 
elements used on the blood, I think we can fairly arrive at a 
conclusion of this kind, that the red corpuscles respond to their 
action, seeing they present us with the same or similar phenomena, 
i.e.y that some are spherical, while others exhibit a partial empty 
condition and assume a discoid form; and others are merely 
empty cells, represented by very delicate circular forms; that 
another class of agents appear to disintegrate the corpuscles in 
such a manner as to exhibit what seems to indicate an external 
envelope, and possibly an internal one as well. It is true some 
observers refer all such changes to chemical action, and regard the 
appearances as due to coagulation, and that there is no true cell 
wall. All that is contended for in answer to such a view is, that 
a differentiation has been effected by the chemical agent used, and 
that this implies a difference in the chemical composition between 
the external and internal portions of a corpuscle ; and again, the 
action of prussic acid on the white corpuscles will sometimes 
exhibit them with a second envelope,' or vesicle attached to the 
nucleus (see diagram) ; and this bears out the view that such a 
corpuscle is a retrograde red corpuscle, i.e., exhibiting not only the 
cell wall of the white corpuscle, but also one which has commenced 
to invest the nucleus. But, in as much as the blood varies from 
time to time in its composition, such a result is not invariably 
obtained; nevertheless, if we do obtain definite results under 
several experiments, we should be prepared to attach some value 
to such changes. 
The operation of delicate tests, such as the above, must be liable 
to be interfered with by what may seem to bo trivial circumstances, 
and the more delicate and more readily decomposable the test, or 
agent is, the more readily will it give evidence of change of 
composition, and so perhaps give rise to uncertainty. "When 
however, the experiment succeeds a given number of times, some 
value should be attached to such results in testing the blood. 
Thus wo find the action of wine on the blood may prevent the 
blue re-action of the prussic acid, and this is explicable on the 
ground that the iron has been pre-occupied by a stronger agent 
derived from the wine, and the blue re-action is suspended for 
a time. 
