ON MUSCARIN. 
365 
freighted, should be locked up securely, so that no one could open it incautiously, and 
on no account should it be unlocked or interfered with, except by daylight. 
“This may not, possibly, be the best arrangement of truck in every respect, but some 
similar arrangement, calculated to preserve inflammable liquids from the atmosphere, 
would render the traffic in such things almost as safe as that of the most ordinary 
goods.” 
ON MUSCARIN, THE POISONOUS ALKALOID OF THE AGARIC US 
MU SC A RI US. 
A remarkable essay has just been published by MM. Schmiedeberg and Koppe on 
Muscarin, the poisonous alkaloid of a certain fungus called the Agaricus muscarius, or 
Amanita muscaria , the properties of which have long been known in connection with 
the curious but not very pleasant story told by Pereira, on the authority of Langsdorf, 
of its use for the purpose of producing intoxication amongst the Russian peasants. The 
alkaloid was obtained, as we learn from an abstract contained in the ‘ Centralblatt,’ 
principally from the specimens of this species growing around Dorpat, though it seems 
probable that it is not limited to this species alone. It is procured by means of a some¬ 
what complicated process through the agency of alcohol, with the addition of acetate 
of lead and ammonia, which leaves the alkaloid in solution, whence, after acidification 
with sulphuric acid, it is precipitated with iodide of potassium and mercury, or potas¬ 
sium-bismuth-iodide. When freed from the latter salts, it appears as a strongly alkaline 
hygroscopic mass, destitute of taste and smell, drying, when evaporated over sulphuric 
acid, into crystalline laminae, easily soluble in alcohol and water, soluble with difficulty 
in chloroform, and not at all in ether. It burns without subliming at a temperature of 
100° C., giving off an odour feebly resembling tobacco. The proportion of the alkaloid 
contained in the agaric is very small, not exceeding ten or twelve grains in two pounds 
of the fresh fungus. As regards its physiological properties they appear closely to re¬ 
semble those of the Calabar bean, and, like this, to be antagonistic to atropine. It acts 
with remarkable energy on cats, a very small quantity injected subcutaneously produc¬ 
ing an abundant flow of saliva and of tears, vomiting, diminution of the frequency of 
the pulse, and such extraordinary contraction of the pupil that this only appeared as a 
narrow black slit. Subsequently dyspnoea and debility of the muscular energy super¬ 
vened, amounting at length to paralysis. Before death the pupil became widely 
dilated ; and the fatal issue resulted from arrest of the respiration, the heart continuing 
for some time to contract feebly. Larger doses were required to kill dogs and rabbits; 
and no contraction of the pupil occurred in the latter. The influence of muscarin on the 
heart was carefully noted in frogs. The subcutaneous injection of the one-tenth of a 
milligramme caused retardation of the heart’s action by prolonging the diastole,—the 
auricle, and then the ventricle, after a few minutes, ceasing to act. For several hours, 
however, the slightest touch of the ventricle induced a single powerful contrac¬ 
tion, showing that the motor apparatus was not paralysed. Section of the vagi caused 
no variation in the phenomena, and hence the authors were led to refer the phenomena 
to a persistent excitation of the inhibitory apparatus situated in the heart itself; and 
the correctness of this view was established by the following control-experiment:— 
Von Bezold and others have shown that atropine paralyses the inhibitory apparatus 
situated in the heart of mammals, and Schmiedeberg has proved in that of frogs also. 
Now it is worthy of notice that a dose of atropine will completely remove the influence 
of muscarin; so that if the heart of a frog has been quiescent for hours, providing its 
irritability is retained, it begins again to pulsate, and to acquire its former activity if a 
dose of atropine be injected, whilst, inversely, muscarin exerts no influence on an atro- 
pinized frog. A similar antagonism exists between muscarin and atropine in regard to 
the heart of mammals. 
In animals poisoned with muscarin the blood-pressure sinks almost immediately to 
one-third of its normal amount. To this primary and principal depression a period 
succeeds during which it slightly rises again. The prodigious fall in the first instance 
is probably due, not simply to retardation of the pulse, but to a sudden loss of tone in 
the vessels,—a loss which is rendered evident in rabbits by dilatation of the vessels of 
the ears. After the injection of atropine the blood-pressure recovers itself again, and 
