57 
containing about 0.061 per cent iodine, and as we have often found 
that the percentage of iodine in a sample of thyroid can be fairly 
accurately determined by these physiological tests, we are inclined 
to believe the analysis correct. Even supposing that the thyroid 
used contained 0.1 per cent iodine, the results show that there is at 
least a general parallelism between the iodine content and the phy- 
siological activity of the thyroid. 
A. SHEEP THYROID; 0.061 PER CENT IODINE. 
Date. 
Weight 
of mouse. 
Remarks. 
1907. 
November 28... 
15. 97 
Feeding of cakes, each containing 0.002 gm. thyroid, commenced. 
30... 
15. 66 
December 3... 
15. 45 
6... 
15. 36 
7... 
15.25 
Acetonitrile, 13.73 mgms., i. e., 0.9 mgm. per gm. mouse. Survived. 
November 28. . . 
18. 04 
Thyroid as above. 
30... 
17.82 
December 3... 
17. 63 
6... 
17. 19 
8... 
17.36 
Acetonitrile, 19.1 mgms., i. e., 1.1 mgms. per gm. mouse. Survived. 
November 28... 
19.99 
Thyroid as above. 
30... 
20. 39 
December 3... 
21.38 
6... 
20.59 
- 
7...| 
20.64 
Acetonitrile, 24.77 mgms., i. e., 1.2 mgms. per gm. mouse. Died, 3 hours. 
November 28.. . 
18.89 
Thyroid as above. 
30.. .j 
18.08 ; 
December 3. . . 1 
17.93 i 
6...! 
17.52 
8... 
17.88 
Acetonitrile, 23.24 mgms., i. e., 1.3 mgms. per gm. mouse. Died, 1 hour. 
B. 
SHEEP THYROID; 0.061 PER CENT IODINE. 
1907. 
November 28. . . 
16.32 
Feeding of cakes, each containing 0.006 gm. thyroid, commenced. 
30... 
16. 24 
December 3... 
15. 77 
6... 
15.52 
7... 
15.72 
Acetonitrile, 23.58 mgms., i. e., 1.5 mgms. per gm. mouse. Survived. 
November 28. . . 
15.06 
Thyroid as above. 
30... 
13. 35 
December 3... 
13.50 
6... 
13.23 
7... 
13.60 
Acetonitrile, 32.64 mgms., i. e., 2.4 mgms. per gm. mouse. Survived. • 
November 28. . . 
17. 62 
Thyroid as above. 
30... 
17.46 
December 3... 
18.06 
6... 
17.78 
8... 
19.05 
Acetonitrile, 59.06 mgms., i. e., 3.1 mgms. per gm. mouse. Survived. 
November 28... 
21.43 
Thyroid as above. 
30... 
20. 97 
December 3... 
20.13 
6... 
19.53 
8... 
19.32 
Acetonitrile, 69.55 mgms., i. e., 3.6 mgms. per gm. mouse. Died, three- 
fourths hour. 
