2 7 s 
M. ARLONlG. 
rofonn produces often at first a slight vaso-dilating action, which 
is followed by a vaso-constriction so much stronger, that it is more 
manifest upon the tracings of rapidity notwithstanding the increase 
of the strength of the systole of the heart; the vaso-constricting 
action diminishes during the third period of the cliloroformization, 
but it is not followed by an inverse action, unless the dose of 
chloroform is toxical. Ether modifies the arterial circulation in 
the same direction as chloral; in advanced etherization, the pulsa¬ 
tions of rapidity present a strong dicrotism ; one observes also a 
retrograde vitess at each pulsation, in such a way that the blood 
column oscillates in the large arteries. 
3d. During chloralization the curve of the venous pressure 
rises and sometimes presents all the pulsations of the arteries. 
During cliloroformization the modifications of the venous press¬ 
ure runs parallel to the arterial. During etherization the two 
pressures oscillate first in the same direction, and later the venous 
pressure rises as in chloralization. 
4th. From the examination of the simultaneous modifications 
of the circulation in arteries and in veins, it results: first, that the 
flowing of the blood in the cajpillaris diminishes some in the 
beginning of chloralization and etherization, to increase much after- 
wards ; second, that this flowing after a short increase, diminishes 
in the beginning of the impregnation by chloroform, to become 
afterwards gradually greater, without however reaching the rapid¬ 
ity that it had in the physiological state. 
5th. The state of the cerebral circulation during anesthesia 
is yet in doubt; for some there is hyperemia at first and anemia 
in the eomfirmed sleep; for others there is, during the sleep, 
cerebral hyperemia. The means used at this day to observe 
these modifications are insufficient and expose one to error. The 
best mode to judge if the cerebral circulation increases or dimin¬ 
ishes in rapidity consists in studying the changes in the rapidity 
of the current of blood in the arteries distributed in the brain, in 
having the cranium intact and to compare these changes witli 
those of the pressure in the blood vessels and corresponding veins. 
In operating in this way, it is seen, first, that all anaesthetics do 
not produce the same effects on the capillary system and that it 
