1194 General Notes. [November, 
centers are interrupted and not continuous in character, and it 
would seem probable that that rate of artificial stimulation which 
most powerfully excites the action of the nerve center is the rate 
at which the center naturally discharges its energy. The follow- 
ing are the results obtained during the research in question: Si 
gle induction shocks applied to the medulla or spinal cord, when 
the connection between these and the brain is severed, have no 
effect upon blood pressure, or only a slight effect, and that when 
the shocks are destructively strong. When middling strong stim- 
uli were used, there was no summation of their effects until the 
separate shocks succeeded each other at least two to three times 
in one second. This slow rate of stimulation produces a greater 
effect in raising blood pressure when the intensity of the single 
shocks is increased. But the strongest stimuli of slow rate pro- 
duce far less increase in blood pressure than stimuli of moderate 
strength and greater frequency. The most favorable rate of stim- 
ulation appears to be that at which the separate shocks succes 
each other at intervals of Iy second. When the intensity te 
mains constant, increase in frequency of stimulation raises bl $ 
pressure, but the maximum is reached when twenty to tuny 
stimuli per second are reached. The maximum effect in ie 
can be produced either through the application of strong sti a 
of the rate 10-12 in onė second or by shocks of medium re 3 
20-25 in a second. The maximum effect upon blood neice i: 
brought about later by the slow succession of strong stimu ©” 
by the rapid weaker stimulation. After the stimulation 1s Drot 
to a close the blood pressure returns very gradually to its no 
level. Dogs and rabbits were the animals experimented "a i 
THE FUNCTION OF THE SPLEEN.— The spleen may bed 
from an animal without apparently producing any speci® 
ance; and though, from its periodical engorgement darie y 
tion, it has been supposed to form a functional part of t 5 
tive apparatus, we are by no means certain of its functions 7 
body. : 
ef 
Herzen comes forward in support of an old view of ` id 
that there is a close relation between the trypsin, oF P of 
ment, producing power of the pancreas and the act tah 
spleen. The author makes an infusion of the pane ae 
ing dog, and finds that it has little or no power to dig with pat 
but if the same pancreas be extracted after mixing it W 
the swollen spleen taken from an mn M full digesti 
reat power of artificially digesting proteids. © ie 
weal at, from varied E erniet, is, that during the rie) 
len condition of the spleen in digestion, there 1s PF ation’ 
special ferment, which being transported by the po partial 
pancreas, there sets up changes which result in the active 
version of the store material of the pancreas into aes 
teolytic ferment, trypsin. 
