82 
Summary . — The results of these experiments may be summarized 
as follows: 
Loss of 
Fatal dose of mor- 
Gm. thv- ; 
Percent- 
Mgm. I in 
weight 
phine m 
mgm. 
roid in 
age of 
thyroid 
in per- 
per gm. 
each 
iodine in 
in each 
cent of 
cake. 
thyroid. 
cake. 
original 
weight. 
Recovered. 
Died. 
A 
• 0.001 
0.085 
0.00085 
6.6 
0.16 
0.15 
B..._ 
.001 
.12 
.0012 
3.3 
.13 
.15 
C i 
.001 ' 
.19 
.0019 
7.6 
.04 
.05 
D 
.001 
.2 
.0020 
7.6 
.05 
.06 
E 
.0005 
.19 
.00095 
4.7 
.11 
.12 
F 
G controls 
.0005 
.2 
.001 
3.6 
1.0 
.09 
.11 
.20 

The fatal dose of morphine sulphate for the rats which had received 
the thyroid with the higher percentages of iodine (0.19 to 0.2) was 
less than one-half as great as that for those which had received the 
thyroid with the lower percentages of iodine (0.085 and 0.12). The 
fatal doses were about the same when but one-half as much of the 
iodine rich thyroid as of the iodine poor thyroid was fed. There 
were but slight losses of weight . 
Series III. 
In this series (which was not very complete) the effects of feeding 
dog thyroid, the iodine content of which had been increased by the 
administration of iodoform to the dogs, were determined. Since the 
experiments will be given in detail in Part II (p. 107-9) of this bul- 
letin only the summary is given here. 
Gm. thy- 
roid in i 
each 
cake. 
Percent- 
age of ! 
iodine in 
thyroid. 
- 
Mgm. 1 in 
thyroid 
in each 
cake. 
Loss of 
weight 
in per- 
cent of 
original 
weight. 
Fatal dose of mor- 
phine in mgm. 
per gm. 
Recovered. Died. 
A 
0.0005 
0.111 
0. 00055 
7.0 
0.25 
B 
. 0005 i 
.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 i 
5. 5 
.25 
F 
.001 
I ’ .3 
. i'V-Thi 
14.0 
.20 
G controls 
9.1 
.39 
.40 
These experiments show that with equal amounts of thyroid 
containing different percentages of iodine those with the higher 
percentages 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 than of the 
iodine rich 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. 
