PHYSIOLOGICAL ACTION, AND ANTAGONISM. 
201 
lessen the tetanising action of ammonia, and this diminution is increased by the 
substitution of two or three atoms, then a change takes place, and when the ammonia 
is combined with four atoms of an alcohol radical, a convulsant action again becomes 
more marked, though it is not so great as in the case of ammonia itself. 
With these exceptions, the symptoms were those of gradual motor paralysis. This 
motor paralysis appeared to us to be due, in a great measure, to a paralyzing action of 
the substance on the spinal cord, as motion ceased in the animal at a time when the 
muscles and motor nerves were still capable of vigorous action. 
The tetramethyl- and tetraethyl-ammonias appear to have a particular tendency to 
paralyse the higher reflexes before the lower, so that reflex from the cornea disappears 
sooner than from the foot. They appear also to affect the heart more than the other 
compound ammonias, so that in poisoning by them the heart was generally found 
motionless, in complete diastole, and distended with dark blood. 
We did not observe the same marked difference between the action of the different 
salts of the compound ammonias that we did in the case of ammonia itself. The 
iodides, however, appear to affect the heart more powerfully than other salts, and to 
cause its arrest in diastole. 
The chlorides and sulphates also appear to have a greater tendency to produce 
muscular tremor than other salts. 
We have drawn up, in a tabular form, an epitome of the symptoms of poisoning 
produced by salts of the compound ammonias in Frogs, Rabbits, and Rats. The 
tables may appear bulky, but the number of salts experimented upon was great, and 
as they were difficult to prepare, and expensive to procure, we have thought it 
advisable to give an .example of the general action of each drug, as well as a summary 
of the results which we have obtained. We have, however, put them as shortly as 
possible, and restricted ourselves to one experiment with each substance on each kind 
of animal. 
2 D 
MDCCCLXXXIV. 
