29 
acetonitrile. The effect is the reverse of the one which was antici- 
pated from certain theoretical considerations and which led us to 
perform the experiments. Inasmuch as the view that one of the func- 
tions of the thyroid is to neutralize poisons is very widely held and, 
since the “ neutralization” (or rendering harmless) of acetonitrile 
in the mouse under the influence of thyroid is the only instance® 
in which a poison is apparently neutralized in any animal — all the 
other 11 poisons” to which reference is so frequently made are purely 
hypothetical — a few words may be devoted to this subject. In the 
first place, there is certainly no reason to suppose that there is any 
direct chemical neutralization of the acetonitrile by the thyroid — 
an interpretation which some have placed upon our previously pub- 
lished results. Not only is it impossible to think of any way in which 
such a neutralization could occur, but the amounts of the nitrile 
which may be rendered harmless are so out of proportion to the 
amounts of thyroid fed that any such interaction is highly improba- 
ble. It was shown in the experiments quoted above that from 1 to 
20 mgm. of thyroid fed during the. course of nine or ten days enabled 
mice to resist the toxic effects of from five to ten times an equal weight 
of acetonitrile. By far the greater part of the thyroid is doubtlessly 
made up of physiologically inert material; hence the disproportion 
between the amount of poison ‘‘neutralized” and the ‘ ‘ neutralizing ” 
agent is still greater. It is interesting to compare in this respect the 
effect of a very active substance — iodothyrine — derived from the 
thyroid. 
Experiment, February 10, 1908: The iodothyrine used in this 
experiment was a commercial preparation (Baeyer) stated to contain 
1 part of iodothyrine mixed with 309 parts of milk sugar; 6 it contained 
0.014 per cent iodine. 
A. IODOTHYRINE (BAEYER). 
Date. 
Weight of 
mouse. 
Remarks. 
1908. 
February 1 
4.. .. 
8 .. ..' 
9.... 
19. 43 Feeding of cakes each containing 0.005 gm. iodothyrine begun. 
18.60 
17. 55 
17.30 Acetonitrile, 43.25 ingms., i. e., 2.5 mgms. per gm. mouse. Survived. 
February 1 
4.. .. 
8 .. .. 
10 .... 
20. 40 Iodothyrine as above. 
19. 76 
19.70 
19. 07 Acetonitrile, 49.58 mgms., i. e., 2.6 mgms. per gm. mouse. Died 1 hour. 
a With the exception of two nitriles closely related to acetonitrile (see p. 20-1). 
b See New and Non-Official Remedies, 3d ed., 1908, p. 74. 
