ATROPINE. 
§ 454-1 
39 1 
atropine to 1 of strychnine, but mixtures in the proportion of 3 strych¬ 
nine and 1 atropine will give distinct mydriasis. 
In such a case, of course, the strychnine should be separated from 
the atropine ; this can be effected by precipitating the strychnine as 
chromate, filtering, and recovering from the filter the atropine by 
alkalising and shaking it out with ether. 
The atropine may be further purified by converting it into oxalate, 
dissolving the oxalate in as small a quantity of alcohol as possible, and 
precipitating the oxalate out with ether ; the precipitate is collected, 
dissolved in as small a quantity of water as possible, the water made 
alkaline, and the base shaken out with ether. 
The most reliable test for atropine, or one of the mydriatic alkaloids, 
is its action on the iris, a solution of atropine even so weak as 
1 : 130,000 causing dilatation. 1 This action on the iris has been 
studied by Ruyter, 2 Donders, and von Graefe. 
The action is local, taking effect when in dilute solution only on the 
eye to which it has been applied ; and it has been produced on the eyes 
of frogs, not only in the living subject, but after the head has been 
severed from the body and deprived of brain. The thinner the cornea, 
the quicker the dilatation ; therefore, the younger the person or animal, 
the more suitable for experiment. In frogs, with a solution of 1 : 250, 
dilatation commences in about five minutes ; in pigeons, seven minutes ; 
and in rabbits, ten minutes. In man, a solution of 1 : 120 commences 
to act in about six to seven minutes, reaches its highest point in from ten 
to fifteen minutes, and persists more or less for six to eight days. A 
solution of 1 : 480 acts first in fifteen to twenty minutes, and reaches its 
maximum in twenty minutes ; a solution of 1 : 48,000 requires from 
three-quarters of an hour to an hour to show its effect. Dogs and cats 
are far more sensible to its influence than man, and therefore more 
suitable for experiment. If the expert chooses, he may essay the proof 
upon himself, controlling the dilatation by Calabar bean ; but it is 
seldom necessary or advisable to make personal trials of this nature. 3 
§ 454. Statistics of Atropine Poisoning. —Since atropine is the active 
principle of belladonna and datura plants, and every portion of these— 
roots, seeds, leaves, and fruit—has caused toxic symptoms, poisoning by 
any part of these plants, or by their pharmaceutical or other preparations, 
1 De Actione Atropce Belladonnce in Iridem, Traj. ad Rhen., 1852. 
2 Arch. Ophthal., ix. 262, 1864. 
3 A. Ladenburg ( Compt. Rend., xc. 92), having succeeded in reproducing atropino 
by heating tropine and tropic acid with hydrochloric acid, by substituting various 
organic acids for the tropic acid, has obtained a whole series of compounds to which 
he has given the name of tropeines. One of these, hydroxytoluol (amygdalic) tropeine, 
he has named homatropine. It dilates the pupil, but is less poisonous than atropine. 
Homatropine when pure does not give a violet hue when evaporated to dryness 
with HN0 3 (Vitali’s test), but the sulphate gives it ; therefore to distinguish it the 
alkaloid must be expelled from the sulphate.—Richmond, An., 1918. 
