23 
thyroid may recover. Only those experiments are quoted which 
show the maximum non-fatal and the minimum fatal dose : 
Series I. 
A. SHEEP THYROID; 0.179 PER CENT IODINE. 
Date. 
Weight 
of mouse. 
Remarks. 
1908. 
February 1 
22.62 
Feeding of cakes each containing 0. 002 gm. thyroid begun. 
4 
23.02 
7 
22. 69 
9 
23. 35 
Acetonitrile, 105.08 mgms., i. e., 4.5 mgms. per gm. mouse. Survived. 
February 1 
22. 56 
Thyroid as above. 
4 
22. 18 
7 
20.62 
TO 
20. 28 
Acetonitrile, 93.29 mgm., i. e., 4.6 mgms. per gm. mouse. Died 2 hours. 
B. CONTROLS. 
1908. 
February 1 
18.83 
Feeding of cakes without thyroid begun. 
4.... 
20. 01 
7.... 
20.19 
10.... 
19.02 
Acetonitrile, 4.76 mgms., i. e., 0.25 mgm. per gm. mouse. Survived. 
February 1 
16.49 
Cakes as above. 
4.... 
15. 56 
7.... 
15. 79 
10.... 
16. 31 
Acetonitrile, 4.24 mgms., i. e., 0.26 mgm. per gm. mouse. Died 10 hours. 
Summary . — The results of these experiments may be summarized 
as follows : 
Gm. thy- 
roid fed 
daily. 
Mgm. I in 
thyroid. 
Weight of 
mouse in 
gms. 
Amount of acetonitrile 
in mgms. 
Result. 
Per mouse. 
Per gm. 
mouse. 
A 
0.002 
0. 0036 
23. 35 
105. 08 
4.5 
Survived. 
.002 
.0036 
20. 28 
93. 29 
4.6 
Died. 
B 
0 
0 
19.02 
4. 76 
.25 
Survived. 
0 
0 
16. 31 
4. 24 
.26 
Died. 
Thus a mouse (A) which had received thyroid recovered from seven- 
teen times the relative amount of acetonitrile fatal to the control. 
Since 0.25 mgm. per gram is the maximum amount of the nitrile from 
which a control (B) recovered, we are justified in assuming that this 
represents the maximum amount of nitrile which the mice of this series 
could, under normal conditions, neutralize; for a mouse weighing 23.35 
gms. this would be a total of 5.84 mgms. The mouse which weighed 
23.35 gms. and which had received thyroid recovered, however, 
from 105.08 mgms. Hence we may conclude that the thyroid had 
enabled the mouse to neutralize, or resist in some way, 99.24 mgms. 
acetonitrile. The mice seldom ate an entire cake (containing 0.002 
gm. thyroid) in a day; hence they had received less than 20 mgms. 
thyroid in all. 
