216 DBS. T. L. BRUNTON AND J. T. CASH ON CHEMICAL CONSTITUTION, 
Experiments on Rats. 
Methyl-, ethyl-, and amyl-ammonium iodides all produce increasing weakness 
with a sprawling or waddling gait. The power of the cord to conduct motor impulses 
appears to be diminished so that the hind legs become more paralyzed than the fore 
legs. Its conducting power for sensory impressions is not paralyzed at this time, as 
stimulation of the hind legs will produce movement in the anterior part of the body. 
In the case of poisoning by amyl-ammonium iodide, twitching of the limbs and head 
were more marked than that of the* methyl or ethyl compounds. 
The dimethyl- and diethyl-ammonium compounds also cause progressive paralysis. 
In the case of the diethyl-ammonium iodide, an occasional instantaneous twitching in 
back and forelimbs was observed, resembling an effort at hiccough. 
The tetramethyl-ammonium iodide has an action very different from the others, 
producing powerful convulsions. It kills also much more rapidly, and is fatal in very 
much smaller dose. 
Experiments on Rabbits. 
In Rabbits the methyl-, ethyl-, and amyl-ammonium iodides all cause increasing 
weakness. The conducting power of the cord appears here also to be affected, the 
hind legs becoming sooner paralyzed than the fore legs. 
In the case of the methyl-ammonium iodide there is a distinct trembling of the 
body not noticed in the other two. 
General Action of the Iodides. 
A distinct alteration appears to be effected in the action of the compound 
ammonias by the combination with iodine. All the iodides, both of ammonia itself and 
the compound ammonias, have a powerful paralyzing action on the motor nerves. 
Muscular irritability is as a rule decreased; occasionally it is increased at first, as in 
the case of the methyl-, ethyl-, and amyl-ammonium iodides. 
The muscle curve in all cases shows a tendency to become humped. This 
tendency is more marked in the methyl, ethyl, and amyl compounds than in the di- 
or trimethyl, ethyl, and amyl compounds. It is more marked when the muscle is 
stimulated directly than when it is stimulated through the nerve. They all render the 
muscle more easily exhausted, so that the tetanic curve becomes lower and is sustained 
for a shorter time. 
