462 Proceedings of the Royal Society 
the salt separates as a heavy oil, which soon crystallises. These 
crystals have the composition C 17 H 23 N0 3 CH 3 I. They are tolerably 
stable, bearing a temperature of 100° C. without much alteration. 
When they are powdered, or when their solution is warmed, a 
pleasant fruity smell is observed. 
Sulphate of methyl- atr opium . — The sulphate was prepared from 
the iodide by the method formerly described for the preparation of 
sulphate of methyl-strychnium, &c. It is a white crystalline salt, 
very deliquescent, and very soluble in water. 
Iodide of ethyl- atr opium . — Iodide of ethyl acts readily on 
atropia, but not so energetically as iodide of methyl. In preparing 
the iodide of ethyl-atropium, atropia was treated with a consider- 
able excess of iodide of ethyl in sealed tubes at 100° C. for an hour. 
The remainder of the process, and the preparation of the sulphate, 
are the same as in the case of the methyl derivative. 
The authors intend, on some future occasion, to describe these 
substances more minutely ; for their present purpose, the descrip- 
tion given above seems sufficient. 
Atropia has a somewhat complicated physiological action, for it 
directly influences the functions of the cerebro-spinal, and also of the 
sympathetic nervous system. 
The action of the methyl and ethyl derivatives on the cerebro- 
spinal nervous system is different from that of the natural base, 
while the action on the sympathetic system is essentially the same. 
The principal effects produced by atropia on the cerebro- spinal 
nervous system are excitation of the spinal cord,* and paralysis of 
the motor and sensory nerves. In a previous paper, the authors 
showed that the spinal stimulant action of strychnia, brucia, 
thebaia, codeia, and morphia, is not possessed by the salts of the am- 
monium bases derived from these alkaloids, but that in its place these 
derivatives possess a markedly different paralysing action on the 
peripheral terminations of motor nerves. They now announce that 
a similar change occurs in the methyl and ethyl derivatives of 
atropia. These derivatives are more powerful paralysing substances 
than atropia itself. 
A considerable amount of spinal stimulant and of paralysing 
action may be produced by a non-fatal dose of atropia ; and it is 
* See Proced. Roy. Soc. of Ed. vol. vi. 1868-69, p. 434, 
