45 
F. CONTROLS. 
Date. 
Weight 
of mouse. 
Remarks. 
1908. 
September 5... 
18. 04 
Feeding of cakes without thyroid commenced. 
9... 
17.50 
12... 
17. 20 
14... 
17. 00 
Acetonitrile, 1.87 mgms., i. e., 0.11 mgm. per gm. mouse. Survived. 
September 5... 
19.78 
Cakes as above. 
9... 
20.50 
12... 
20.56 
14... 
20. 29 
Acetonitrile, 2.64 mgms., i. e., 0.13 mgm. per gm. mouse. Died 2J hours. 
September 5... 
21. 14 
Cakes as above. 
9... 
20.52 
12... 
20. 48 
14... 
20.22 
Acetonitrile, 3.03 mgms., i. e., 0.15 mgm. per gm. mouse. Died 3 hours. 
September 5... 
21.32 
Cakes as above. 
9... 
22. 16 
12... 
22. 40 
13... 
Acetonitrile, 4.03 mgms., i. e., 0.18 mgm. per gm. mouse. Died 5 hours. 
SUMMARY. 
Thyroid. 
Gm. thy-,, 
roid fed 
daily. 
Percent- 
age of 
iodine in 
| thyroid. 
Mgm. I in 
thyroid fed 
daily. 
Fatal dose of ace- 
tonitrile in mgms. 
per gm. 
Recovered. 
Died. 
A. Maltese kid 
0.01 
0 
0 
0. 25 
0. 27 
B. Alaskan bear 
.01 
0 
0 
.50 
.53 
C. Children 
.01 
0 
0 
.53 
.57 
D. Black leopard 
.01 
.01 
.001 
.27 
.30 
E. Sheep 
.001 
.125 
. 00125 
1. 60 
1. 70 
F. Controls 
. 11 
. 13 
The three iodine free thyroids (A, B, and C) protected mice against 
more than twice the dose of acetonitrile fatal to the controls; those 
of the Alaskan bear and of children were about twice as active as that 
of the Maltese kid. The thyroid of the black leopard, although it 
contained a small percentage of iodine, was only about half as active 
as the thyroids of the Alaskan bear and of the children. One one- 
thousandth of a gram of sheep thyroid, containing 0.125 per cent 
iodine, protected against about three times as much acetonitrile as 
did ten times as much of the iodine free children’s thyroid; we may 
therefore conclude that it was about thirty times as active as the 
latter. 
