109 
G. CONTROLS. 
Date. 
Weight 
of rat. 
Remarks. 
1908. 
May 15 
41 
Feeding of cakes without thyroid commenced. 
18 
38 
20 
37 
23 
38 
26 
40 
Morphine sulphate, 13.6 mgms., i. e., 0.34 mgm. per gm. rat. Survived. 
May 15 
41 
Cakes as above. 
18 
39 
20 
37 
23 
36 
28 
36 
Morphine sulphate, 14 mgms., i. e., 0.39 mgm. per gm. rat. Survived. 
May 15 
50 
Cakes as above. 
18 
46 
20 
48 
23 
44 
27 ! 
44 
Morphine sulphate, 17.6 mgms., i. e., 0.4 mgm. per gm. rat. Died 4 hours. 
Summary . — These experiments may be summarized as follows: 
Gm. thy- 
roid in 
each cake. 
Percentage 
of iodine in 
thyroid. 
Mgm. I in 
thyroid of 
each cake. 
Loss of 
weight in 
per cent of 
original 
weight. 
Fatal dose of mor- 
phine sulphate in 
mgm. per gm. 
Recovered. 
Died. 
A 
0.0005 
0.111 
0. 00055 
7.0 
0.25 
B 
.0005 
.3 
.0015 
7. 6 
.20 
0. 25 
C 
.0015 
.111 
.00166 
2.4 
.25 
D 
.003 
.111 
.00333 
.0 
.16 
.20 
E 
.001 
.106 
.00106 
5.5 
.25 
F 
.001 
.3 
.0030 
14.0 
.20 
G. Controls 
9.1 
.39 
.40 

These experiments show that with equal amounts of thyroid con- 
taining different percentages of iodine those with the larger amounts 
of iodine caused the greater lowering of resistance to morphine; also 
that in order to obtain equal physiological effects it was necessary 
to feed much more of the iodine-poor thyroid. Loss of weight can 
not explain the increased susceptibility of the rats to morphine, for 
with but one exception there was no loss of weight greater than that 
which could be ascribed to the exclusive cracker diet. 
SERIES B. 
Twenty-three dogs were divided into three groups. There 
were six dogs in the first group (Group 6), nine in the second 
(Group 7), and eight in the third (Group 8). Each of the dogs of 
Group 6 received about 1.2 grams iodoform in capsules on two suc- 
cessive days; they were killed on the day following that on which 
they had received the second dose. The glands were weighed and 
dried as described under Series A, 
