70 
C. THYROID; 0.065 PER CENT IODINE. 
Date. 
Weight of 
mouse. | 
Remarks. 
1908. 
September 24. . . 
13.35 
F ceding of cakes each containing 0.001 gm. thyroid commenced 
28...' 
13.34 ! 
October 2 
12.54 
i Acetonitrile, 5.64 mgms., i. e., 0.45 mgm. per gm. mouse. Survived. 
September 24... 
12.70 
Thyroid as above. 
28... 
12.36 
October 2 
11.58 
3 
Acetonitrile, 5.79 mgms., i. e., 0.50 mgm. per gm. mouse. Survived. 
September 24.. . 
16.10 
Thyroid as above. 
28... 
16.24 
October 2 ; 
15.97 
3 1 
Acetonitrile, 9.26 mgms., i. e., 0.58 mgm. per gm. mouse. Died 2| hours. 
September 24... 
20.88 
Thyroid as above. 
28...} 
20.62 
October 2 
17.73 
Acetonitrile, 12.41 mgms., i. e., 0.7 mgm. per gm. mouse. Died 1 hour. 
D. THYROID; 0.065 PER CENT IODINE. 
1908. 
September 24.. . 19. 55 I Feeding of cakes each containing 0.005 gm. thyroid commenced. 
28...! 19.90 
October 2 19.13 | Acetonitrile, 22.96 mgms., i. e., 1.2 mgms. per gm. mouse. Survived. 
September 24. . . 13. 89 I Thyroid as above. 
28... 13.70 I 
October 2 13. 60 
3 Acetonitrile, 21.76 mgms., i. e., 1.6 mgms. per gm. mouse. Survived. 
September 24... 18.60 Thyroid as above. 
28... 18.20 
October 2 j 17.00 i 
3 | Acetonitrile, 32.3 mgms., i. e., 1.9 mgms. per gm. mouse. Survived. 
September 24.. . 13.15 I Thyroid as above. 
28...} 13.06 
October 2 10.55 Acetonitrile, 21.10 mgms., i. e., 2 mgms. per gm. mouse. Died 21 hours. 
SUMMARY. 
} Gm. thy- 
roid fed 
daily. 
Percentage 
of iodine 
in thyroid. 
Mgm. I 
in thy- 
roid fed. 
Fatal dose of ace- 
1 tonitrile in mgms. 
per gm. 
Recovered. 
Died. 
A 
0.001 
0.38 
0.0038 
1.8 
2.0 
B 
.005 
.38 
.019 
4.2 
C.; 
.001 
.065 
.00065 ' 
.5 
,58 
D } 
E. Controls 
.005 
.065 
.00325 1 
1.9 
2.00 
.1 
Five times as much, thyroid was required in D as in A to produce 
a given physiological effect ; this difference corresponds fairly closely 
with the differences in the percentages of iodine. 
Many other experiments with results similar to the above were 
performed; a number of them will be reported later in other connec- 
tions. More than twenty preparations of commercial desiccated 
thyroids were examined and, with possibly one exception, their 
