7 

 7 



>! 

 !> 



and 10 seconds 



10 

 19 

 20 



)> 

 )) 





20 



!> 



and 20 seconds 



26 



>) 





26 



>> 



and 20 seconds 



706 DRS CRUM BROWN AND FRASER ON THE CONNECTION BETWEEN 

 5 minutes after the injection, the heart was contracting 28 times in 10 seconds. 



the right vagus was galvanised* for ten seconds, and the heart con- 

 tinued to contract, during the galvanism, 28 times in 10 seconds. 



the heart was contracting 29 times in 10 seconds. 

 >> j) 30 „ ,, 



the left vagus was galvanised for ten seconds, and the heart con- 

 tinued to contract, during the galvanism, 30 times in 10 seconds. 



the heart was contracting 30 times in 10 seconds. 

 >> >j 30 „ „ 



the right vagus was galvanised for ten seconds, and the heart con- 

 tinued to contract, during the galvanism, 30 times in 10 seconds. 



No general symptoms of the action of sulphate of methyl-atropium were de- 

 veloped during this period, the dose that was administered being but small. 



The paralytic action on the inhibitory cardiac branches of the vagi, which this 

 experiment clearly exhibits, would appear to be a very powerful one ; for it was 

 not counteracted, within twenty minutes, by half a grain of extract of physo- 

 stigma subcutaneously administered, nor, within thirty minutes, by a second dose 

 of three-fourths of a grain of extract of physostigma, administered twenty minutes 

 after the first. 



In other similar experiments on rabbits, we succeeded in completely para- 

 lysing the vagi nerves with one-tenth and with one-twentieth of a grain of 

 iodide of methyl-atropium, and with one-tenth of a grain of iodide of ethyl- 

 atropium. 



We have seen, from Experiments VII., VIII., XXXII, and XXXIV., that 

 iodide and sulphate of methyl-atropium, when acting through the blood, produce 

 marked dilatation of the pupils. A number of experiments were made to deter- 

 mine whether the topical application of these salts to the conjunctiva similarly 

 affects the pupil, and, thus, further exhibits a similarity in action to atropia and 

 its salts. 



The largest dose we applied was the -g-J-oth of a grain. 



Experiment CXI. — This dose, dissolved in one minim of distilled water, was 

 applied to the left eyeball of a rabbit, and it caused extreme dilatation of the 

 left pupil (f$ths x J^ths of an inch) in less than five minutes, which lasted 

 for more than three days. The left pupil was of normal size on the sixth 

 day. 



In order to test the delicacy of this reaction, we made the following experi- 

 ments : — 



Experiment CXII. — One minim of a solution of one grain of sulphate of 

 methyl-atropium, in 1000 minims of distilled water ( = 10 1 o0 th of a grain of 

 sulphate of methyl-atropium), was placed on the right eyeball of a rabbit. 



* Throughout the experiment the strength of the galvanic current was the same as that 

 which produced stoppage of the heart's contractions before the administration of sulphate of methyl- 

 atropium. 



