On November 21 the blood sugar was lowered from 0.43 per cent at
10:15 A.M. to 0.3 per cent at 2 P.M by the subcutaneous injection of 20 c.c.
of Berkefeld extract. On November 22, 10 c.c. of a freshly prepared concen-
trated extract of fetal calf pancreas was injected subcutaneously with the
remarkable result that the sugar of the blood fell from 0.40 per cent at
4 P.M. to the subnormal level of 0.075 per cent at 9 P.M. On November 24 at
10 P.M., 10 C.C. of a seven days' old extract containing 0.7 per cent tricresol
caused the percentage of blood sugar to fall from 0.43 to 0.22 per cent at
11:15 A.M. On November 28 at 9:30 A.M. the blood sugar was 0.43 per cent
and 10 gm. sugar in 100 c.c. of water injected intravenously raised it to 0.60
per cent and 8.53 gm. of sugar were excreted in the urine in the four hours
following the injection. We were unable to follow the blood sugar curve as
closely as desirable owing to the difficulty of obtaining blood by venepuncture.
At 6 P.M. on the same day 6 c.c. of a more concentrated fetal calf extract were
given subcutaneously and next morning (at 9:30 A.M. November 29), the
blood sugar was found to be 0.18 per cent when 4 c.c. of the same extract
was again injected. The blood sugar at 2:30 P.M. was 0.048 per cent and the
urine collected from 9:30 A.M. to 3 P.M. was sugar free, the volume excreted
between 12 noon and 3 P.M. being 68 c.c. At 3 P.Ma., 4 c.c. extract was admin- J
istered and at 4 P.M. 10 gm. of sugar in 100 c.c. of water were injected intra-
venously. The blood sugar at 7:30 P.M. was 0.05 per cent and in the two
hours following the injection of sugar 0.51 gm. were recovered in the urine
after which the urine was free of sugar. On November 30 the animal was
in good condition. On December 1 it excreted 14.84 grams of sugar in a
volume of 520 c.c. of urine and on December 2, 320 c.c. of urine and 10.94
gm. of sugar.
At 10 A.M. on December 3 after eighteen hours' starvation the blood sugar
was 0.28 per cent when 10 c.c. of concentrated fetal calf extract were given
by stomach tube in order to find out whether absorption of the active prin-
ciple of the extract might occur through the gastric mucosa. At 2 P.M. the
blood sugar stood at 0.23 per cent when another 10 c.c. of extract were given
by mouth. The blood sugar rose slightly during the next hour. On the fol-
lowing days December 4, 5 and 6 the animal excreted 4.95, 8.40 and 15.70
grams of sugar respectively.
Since the animal at this stage was still in fairly good condition, even
though there had been considerable irregularity in the administration of ex- I
tract, it was decided to discontinue using it for the purpose of testing the J
relative potency of different forms of extract and to administer to it the most
efficient of these in regular dosage so as to determine for how long a time
the animal could be kept alive. On December 7 the injection was made with
fetal calf extract prepared as described above, but on December 8 an extract,
prepared by extracting the pancreas with alcohol, evaporating to dryness
and redissolving the residue in distilled water, was used with the result that
4 c.c. caused the blood sugar to fall from 0.30 to 0.15 per cent in one hour.
A second injection of this extract (12 c.c.) was given at 1 P.M. and at 5 P.M.
the blood sugar was 0.12 per cent. It will be seen that the principle upon