214 MM. Schmidt and Stiirawage on the Effects produced 
of tyrosine. This quantity corresponds to 1°77 per cent. of the 
fresh pancreas, or, since that contains 76 to 77 per cent. of water, 
to 7:37 per cent of the solid constituents. A subsequent experi- 
ment, made with a fresh pancreas under special precautions, 
showed that leucine pre-existed in the gland, and was not a pro- 
duct of decomposition. 
Professor Schmidt and Dr. Stiirzwage in Dorpat have made 
a series of experiments on the action of arsenious acid, when in- 
troduced into the* circulation, on the oxidizing process in the 
body. The mode of experimenting consisted in determining the 
normal quantity of carbonic acid exhaled in an hour by certain 
animals (fowls, pigeons, and cats), and then administering to them 
arsenious acid, and again observing the quantity of gas exhaled 
in the same time. The apparatus consisted of a bell-jar, stand- 
ing on a ground-glass plate, under which the animal was placed. 
In the tubulure of the bell-jar were inserted two tubes, and a 
delicate thermometer. One of these tubes communicated freely 
with the air, the other was connected with a series of tubes for 
the absorption of carbonic acid and water, and with an aspirator 
by which a regulated quantity of air could be drawn through the 
system. Each experiment lasted about an hour, during which 
time about 80 to 35 litres of air were drawn through: the car- 
bonic acid of this air was determined by a separate experiment, 
and allowed for. The secretion of urea was determined in some 
cases: the determinations were made by Liebig’s method, 
A fowl weighing 896 grms. was found to respire on an 
average 2°07 grms. CO? in the hour. A solution of 0°018 grm. 
arsenious acid was then introduced into its crop, and after half an 
hour the bird was placed under the jar. It was found to respire 
1:88 grm. of CO? in the hour. On the next day 0°027 grm. of 
AsO? were administered; the quantity of CO? diminished to 
1:35 grm.; at the same time the bird was attacked by severe 
diarrhoea, its respiration became greatly accelerated, it drank 
much water, and trembled violently. On the following day 
these symptoms diminished, and 0-035 grm. AsO® were injected. 
Three hours after, the expiration of carbonic acid diminished to 
1°296 germ. 
In an experiment with another fowl, the injection of 0-032 
grm. AsO® caused the respiration to diminish from 2°085 grms. 
in the hour to 1°75 grm. 
In another fowl weighing 1400 grms., the respiration of CO? 
was 2°37. An hour and a half after the injection of 0:035 AsO? 
it fell to 1:92 grm., and ten hours after to 1:37 grm. It showed 
at the same time the usual symptoms of arsenical poisoning, but 
afterwards gradually recovered, and in five days its respiration 
