PHYSIOLOGICAL ACTION, AND ANTAGONISM. 
217 
Sulphates. 
Experiments on Frogs. 
Ammonium sulphate soon causes the movements to be accompanied with twitchings 
aud clonic spasm. It sometimes, though rarely, produces complete tetanus; the 
peripheral ends of motor nerves are paralyzed by it, and the muscular substance is 
also paralyzed, though later than the nerve. 
The heart is considerably affected by the poison, and is frequently found arrested in 
diastole, and filled with dark blood. In this point it appears to agree with the iodide. 
Methyl, ethyl, and amyl sulphates all cause gradually increasing lethargy and failure 
of reflex movement. 
Methyl-ammonium sulphate paralyzes muscle and nerve very completely, the nerve 
being paralyzed before the muscle. The ethyl- and amyl-ammonium sulphates have 
much less paralyzing action upon muscle and nerve, but render them liable to rapid 
exhaustion. 
In poisoning by them the heart was considerably affected, and beat very slowly ; pro¬ 
bably the slighter effect on the muscle of ethyl and amyl sulphates in our experiments 
was due to their greater effect upon the heart, so that they were carried in lesser 
quantity to the muscle. This is exactly what one finds with such a poison as vera- 
trine, which has an extraordinary effect on the muscle of a Frog in small doses, but 
has little effect on the muscle when the dose is large, the heart being so quickly 
arrested that but little effect is produced upon the muscle. 
Dimethyl- and diethyl-ammonium sulphate both cause weakness, with tremulous 
movement; but in the case of diethyl-ammonium sulphate, strong irritation causes a 
powerful movement in the limbs, occurring after a considerable latent period. The 
nerve appears to be powerfully paralyzed by the dimethyl-ammonium sulphate, while 
the paralyzing action is but slightly marked in the case of the diethyl-ammonium 
sulphate ; the paralysis of the muscular tissue is also more marked in the case of the 
dimethyl-ammonium sulphate (Plate 8, fig. 6, a , b). Both lessen the activity of the 
circulation, and render the cardiac pulsations slow. 
The trimethyl- and triethyl-ammonium sulphates both cause the movements to 
become weaker and tremulous, and sometimes staccato. 
The trimethyl-ammonium sulphate (Plate 8, fig. 7, a, b, c, cl) appears at first to 
increase the excitability of the animal, and even when the muscular power has failed, 
so that irritation of the foot no longer will cause it to be withdrawn, tremor occurs 
over the whole body from the stimulus. The nerve is either much weakened or 
paralyzed, so that it either soon gives way when tetanised, or does not respond to 
stimulus at all. The muscle is also paralyzed; the minimal irritability is much 
impaired in poisoning by trimethyl-ammonium sulphate, although the contractile 
power remains considerable. 
One of the most marked points in the action of the sulphates of ammonia and 
MDCCCLXXXIV. 2 F 
