208 PROFESSOR RUTHERFORD ON THE 
It is interesting to observe that in Experiment 53a the dose, which, in rela- 
tion to the size of the animal, was twice as great as in Experiment 53, raised 
the coefficient of secretion to a little more than twice the figure attained in 
Experiment 53, showing forcibly the precision of the experimental method 
employed. The high coefficient in Experiment 53a indicates a very powerful 
effect; yet, since the dose employed was four times the maximum dose for a 
man, and seeing that one grain produced only a trifling effect in Experiment 
53, it may be inferred that, in the human subject, physostigma will probably be 
found to have, in the relatively small doses administered, an insignificant effect 
on the liver ; for many of the preceding experiments have demonstrated that, 
when the same dose of a substance that powerfully excites the human liver is 
given to an average-sized dog, it powerfully excites its liver. It is an error to 
suppose that the dog requires much larger doses of all drugs than are necessary 
for the human subject. The effect of physostigma on the liver is completely 
antagonised by atropia sulphate. 
Prevost of Geneva, in a communication to the Paris Academy of Scions 
(August 3, 1874), states that muscaria increases the biliary secretion, and that 
atropia checks the hypersecretion due to muscaria. 
ACTION OF ATROPIA. 
It is known that atropia causes purgation and diuresis in dogs (Op. viii. 
p. 322). On the other hand, it paralyses the chorda tympani and the secretory 
nerves of the sweat and milk glands, and thereby arrests their secretions. It 
therefore seemed desirable to give atropia previous to the administration of any 
other substance, in order to determine its influence on the liver. 
Experiment 54. Dog that had fasted eighteen hours. Weight 16:1 kilo- | 
grammes (fig. 54.)—In this experiment the secretion of bile rose at the end | 
of the first hour, although no drug had been administered. Our previous 
experiments have convinced us that this is due to reaction, which is apt to — 
ensue unless great care is taken to pull as little as possible at the bile-duct | 
during the operation for inserting the cannula. | 
Half a grain of atropia sulphate, dissolved in twenty minims of water, was | 
injected into the jugular vein at a, a’, a’, and again at a”; and one grain was | 
injected at @’””. Thus three grains were given in all. The fall of secretion 
after the first dose may be discarded, as it would probably have taken place | 
had no atropia been given. It is evident that the atropia does not arrest the | 
secretion of bile as it does that of saliva, sweat, and milk. Nor can it be said | 
to augment it; for the increased secretion that followed the third dose is | 
trivial, and may be discarded in view of the sequel to the second dose m 
Experiment 53a. 
