434 



Mr. W. H. Jessop. On the Mydriasis [Juue 18, 



an increase in the mydriasis occurs very quickly. The increase does 

 not act to light or accommodation. 



A. G., 16. Under atropine (4 grains to the ounce three times a 

 day for ten days), both pupils 9 mm. and equal, not acting to light or 

 movements of accommodation. In left eye cocaine 4 per cent., and 

 in fifteen minutes pupil 10 mm. 



In one case, however, in which atropine had been used for two 

 months continually, the pupil was very much dilated, 10'5 mm., and 

 here cocaine had no effect, the pupil being at its ad maximum dilata- 

 tion. 



F. G., 17. Has been using atropine for two months; pupils equal, 

 regular, 10'5 mm., there being a very thin ring of iris visible; five 

 applications of cocaine 4 per cent, in right eye, and no effect on the 

 size of pupil. 



The results of these two experiments led me to make a mixture of 

 the two drugs, and by it an ad maximum dilatation of the pupil can 

 be soon produced, which will not soon disappear like cocaine my- 

 driasis. 



The good effects of this in iritis were pointed out by me last 

 January, and since have been fully sustained by increased experience. 



E. G., 6. Pupils 5 mm., equal, act well to light and accommoda- 

 tion ; at 2.24 p.m. a gelatine disk (of cocaine grain and atropine 

 "soVo grain) put on left cornea ; at 2.29 p.m. no effect on pupil, slight 

 drooping of lower lid. 



2.34 p.m., pupil 9 mm. when shaded, 6 mm. in lighb, or on accom- 

 modating. 



2.40 p.m., pupil 10 mm., acting slightly to light and accommodation. 



2.42 p.m., pupil 11 mm., does not act to light and accommodation. 



In this case, then, in eighteen minutes we had an ad maximum dila- 

 tation of the pupil. To test the difference in time between this and 

 the action of the same quantity of atropine alone, the next experiment 

 was done. This shows that in eighteen minutes no effect was noted on 

 the pupil, and that in thirty-six minutes the pupil was only 9 mm., 

 and the greatest dilatation attained was 9'5 mm. 



E. G., 6. 2.46 p.m., right eye, pupil 5 mm., atropine disk 50 1 00 grain. 



2.58 p.m., no effect. 



3.4 p.m., no effect. 



3.17 p.m., pupil 8 mm., does not act to light or accommodation. 

 3.22 p.m., pupil 9 mm. 



3.45 p.m., pupil 9'5 mm., and did not increase. 



Experiment IV. — Cocaine and Eserine. 



The action of eserine on cocaine mydriasis was to induce myosis 

 very easily. The myosis resembled that due to eserine alone. 



On investigating more carefully I found that on taking 2 per cent. 



