558 Proceedings of the Royal Society 
and hydrochlorate of tri-methylamine develop their full effects 
sluggishly ; but the different structures which they influence have 
their activity destroyed nearly simultaneously, so that it is a 
matter of considerable difficulty to ascertain whether the muscles 
are paralysed before the motor nerves, or the latter before the 
sensory, or whether the nerve-trunks or periphery are first affected. 
Iodide of tetra-methyl-ammonium, however, very rapidly destroys 
the conductivity of the motor nerves by an action on their peri- 
pheral terminations, and an interval of several hours may elapse 
before its other effects are fully developed. 
While the change of physiological action, produced by the addi- 
tion of iodide of methyl to tri-methylamine, differs in some respects 
from that produced by the performance of the same operation upon 
strychnia, the observations now communicated tend to confirm the 
conclusion drawn from the previous experiments of the authors, 
that paralysis of the peripheral terminations of motor nerves is a 
characteristic effect of the salts of the ammonium bases. 
The decomposition of atropia by means of acids and bases has 
lately been completely studied by Kraut* and by Lossen.f It 
appeared of interest to examine the physiological actions of the pro- 
ducts of this decomposition, and to compare them with that of 
atropia. The reaction may be expressed by the equation — 
G )7 H 23 N0 3 + H 3 0 = c 9 h 10 o ;) + C 8 H 15 N0 
Atropia. Water. Tropic acid. Tropia. 
The tropic acid is further changed by loss of water into two 
isomeric acids, atropic and isatropic (C 9 H 8 0 2 ), the former being 
produced most abundantly in the presence of alkalies, and the 
latter in the presence of acids. These substances were prepared by 
the methods given by Kraut and by Lossen; and, on account of the 
readiness with which the acids pass by oxidisation into formic and 
a toluic acids, the action of the latter acid, prepared by the method 
which one of the authors communicated to this Society some years 
ago,J was also examined. 
Each of these substances has been examined by the authors, and 
it was found that none of them possesses the well-known dilating 
* Annalen der Chem. u. Pharm., cxxviii. 280; cxxxiii. 87; cxlviii. 238. 
t Ibid, cxxxi. 43 ; cxxxviii. 230. 
J Proceed. Koy. Soc. Edin. v pp. 409, 455. 
