708 DRS CRUM BROWN AND FRASER ON THE CONNECTION BETWEEN 



It seemed to us unnecessary to proceed further in our examination of the 

 delicacy of this action on the iris. The researches of De Ruyter have placed at 

 our disposal a number of experiments with sulphate of atropia, similarly applied 

 in extremely dilute solutions. From these researches we learn that a drop of a 

 solution containing the xrsWoth °f a grain of sulphate of atropia is capable of 

 producing dilatation of the pupil in a dog, which lasts for eighteen hours.* Com- 

 paring this result with that obtained in our experiment with the loryWo^h of a 

 grain of sulphate of methyl-atropium, we are justified in considering that the 

 addition of sulphate of methyl to atropia does not diminish the mydriatic action 

 of this alkaloid to any marked extent. 



Iodide of etltyl-atr opium (C 17 H 23 N0 3 CH 3 I). — Our investigation also includes 

 an examination of the physiological action of this ethyl derivative of atropia. The 

 results of this examination prove that this substance acts in precisely the same 

 manner as the previously described methyl derivatives. 



Iodide of ethyl acts readily on atropia, but not so energetically as iodide of 

 methyl. In preparing the iodide of ethyl-atropium, atropia was treated with a 

 considerable excess of iodide of ethyl, in a sealed tube, at 100° C, for an hour. 

 The remainder of the process is the same as in the case of the methyl derivative, 

 which in general appearance and character it closely resembles. 



We found that two grains of this substance, administered by subcutaneous 

 injection, is a poisonous dose for a full-grown rabbit. 



Experiment XLVIII. — In a rabbit, weighing three pounds and seven ounces, 

 it was found that the right pupil, under exposure to a full light, had a diameter 

 of |-g-ths x ££ths of an inch, and that the respirations were irregular and at the 

 rate of twenty-four in ten seconds. 



A solution containing two grains of iodide of ethyl-atropium, in one hundred 

 and twenty minims of slightly warmed distilled water, was then injected under 

 the skin at the back of the rabbit. In two minutes, the pupils measured 

 £-gths x i-Jths. In three minutes, the respirations occurred regularly at the rate 

 of twenty per ten seconds ; but there was no other symptom present. In six 

 minutes, some faint quivers occurred, and a slight degree of paralysis was pre- 

 sent. The latter gradually increased in severity until, in sixteen minutes, the 

 rabbit was unable to move about, and lay on the abdomen with the head resting 

 on the table in an utterly flaccid state. The respirations were now shallow and 

 somewhat jerking in character, and they occurred at the rate of fourteen per ten 

 seconds. In twenty-two minutes, the respirations were extremely feeble, and at 

 the rate of only nine per ten seconds, After this, they quickly diminished in 

 number, until they altogether ceased in twenty-four minutes after the injection. 

 At the time of the occurrence of death, the pupils measured |fj- ths x |£ths °f an 

 inch. 



* Quoted by Meuriot, op. tit. p. 118, from Nederlandsch Lancet, 1853. 



