220 DRS. T. L. BRUNTON AND J. T. CASH ON CHEMICAL CONSTITUTION, 
Variations in Action according to the Acid Radical. 
Chlorides. 
{a.) Irritability is, as a rule, slightly increased. 
(b.) Tetanus from the muscle is often more extensive, whilst that from indirect 
stimulation is less extensive than on the normal side. 
(c.) The curve is often exaggerated in direct stimulation. 
It is frequently higher, and may be slightly shorter or longer than normal. On 
repeated stimulation, whether direct or indirect, the curve elongates to a greater or 
less extent. There is, as a rule, less elongation, less succeeding contraction, and less 
tendency to develop a distinct second hump than is to be seen in the iodides. 
(■ d .) The nerve gives way somewhat before the muscle, but these substances 
( i.e ., chlorides) are not so fatal to nervous irritability as are the iodides. Amyl- 
ammonium chloride has a relatively stronger action on nerve than on muscle. 
Iodides. 
(a.) Irritability is, as a rule, decreased, the exception being occasionally found 
in ethyl-ammonium iodide, and di- and triethyl-ammonium iodides. 
(b.) Tetanus is diminished in extent in almost every case. 
(c.) The curve shows a strong inclination in all, but most in those lowest in the 
series, to become two-humped, the second horn or hump passing into a contracture, 
with very gradual decline. 
(d.) In all cases the nerve becomes paralyzed much before the muscle. 
Sulphates. 
(a.) Minimal irritability is increased, or normal in the case of ethyl-ammonium 
sulphate, cliethyl-ammonium sulphate, and triethyl-ammonium sulphate. It is 
decreased by amyl-ammonium sulphate, and by all the methyl-sulphates. 
( b .) Tetanus produces more extensive contraction on direct stimulation in the case 
of the ethyls, and in very slight poisoning in some instances in the methyls, but in the 
latter it is usually diminished. 
(c.) The curve is chiefly affected by the methyl compounds, on which it is usually 
lower and longer, and shows increased viscosity. It seldom displays the strong 
tendency to the double hump form which is so common amongst the iodides. 
In the ethyl compounds the curve is usually somewhat exaggerated in relationship 
to the normal. 
(d.) The failure of the nerve occurs somewhat sooner than that of the muscle. This 
is much more marked in the methyl than in the ethyl compounds. 
On summing up those results, it appears that the iodides paralyze motor nerves 
more quickly than either chlorides or sulphates. We did not observe any marked 
