CHEMICAL CONSTITUTION AND PHYSIOLOGICAL ACTION. 705 



312 grains, was exposed, the blood-vessels that entered it were carefully ligatured, 

 and all the connections of the muscle divided, except its origin and insertion. 

 Immediately afterwards, a solution of one-tenth of a grain of sulphate of methyl- 

 atropium, in five minims of distilled water, was injected under the skin of 

 the back. Paralytic effects were quickly produced. In fifteen minutes, the 

 left sciatic nerve was exposed and stimulated by galvanism, with the result 

 that while no contraction was produced in the left limb, energetic movements 

 occurred in the right. The right sciatic nerve was then exposed and subjected 

 to galvanic stimulation ; energetic movements occurred in the right leg, which 

 were ascertained to be entirely caused by contractions of the gastrocnemius 

 muscle (non-poisoned) ; and no movement occurred elsewhere. On directly 

 galvanising the poisoned muscles it was found that their contractility was still 

 retained. 



We learn from Experiments XLIII. and XXXVIII. that sulphate of methyl- 

 atropium does not paralyse the motor nerve trunks. We further learn from 

 Experiment XLIL that certain terminations of a motor nerve protected from 

 the direct action of this poison are not paralysed, while other terminations 

 exposed to its action are very quickly paralysed. It is, therefore, apparent that 

 the paralysis of the motor nerves, which this substance so energetically produces, 

 is due to an action that is restricted to their peripheral terminations. 



The valuable and interesting researches of Botkin,* Von Bezold and 

 Bloebaum,t Meuriot,| and others, have shown that atropia exerts a para- 

 lysing influence on the inhibitory cardiac branches of the vagi nerves. When 

 administered, even in very small doses, this substance so completely paralyses 

 these nerves, that powerful galvanic stimulation of the main trunk of one of 

 the vagi does not produce stoppage of the heart's action, or even appreciably 

 diminish the rate of its contractions. It seemed important that we should 

 determine if the methyl and ethyl derivatives of atropia possess this remarkable 

 action. 



Experiment XXIX. — The two vagi nerves were exposed in the neck of a 

 rabbit, weighing three pounds and eight ounces. On subjecting each vagus 

 separately to galvanic stimulation of a certain strength, obtained by the use of 

 Du Bois Reymond's induction apparatus, it was found that total stoppage of the 

 heart's contractions resulted on each occasion, during the ten seconds the gal- 

 vanic stimulation was applied. A solution containing half-a-grain of sulphate of 

 methyl-atropium, in fifteen minims of distilled water, was injected under the skin 

 of the abdomen. 



* Virchow's Archiv. Bd. xxiv. 1862, p. 89. 



f Untersuchungen aus dem Physiologischen Laboratorium in Wiirzburg, ltes heft, 1867, p. 43. 

 I De la Method Physiologique en Therapeutique et de ses Applications a l'etude de la Bella- 

 donne, 1868, p. 76. 



VOL. XXV. PART II. 8 X 



