260 



HOLMES. 



low concentration of iodine an increase in the concentration of the 

 iodine in the solution is attended by a greater increase in the iodine in 

 the reaction product than is the case with the other alkaloids, while 

 a point is soon reached with higher concentrations where further incre- 

 ment in iodine concentration has but little effect. This may possibly 

 be interpreted as evidence of a tendency toward the formation of a 

 definite periodide, although no concomitant tendency toward a definite 

 crystal form was observed. N"o indication was apparent of an inclina- 

 tion toward the formation of any defkiite periodides in the experiments 

 with morphine and codeine. 



A series of experiments was then made to detennine in how far the 

 precipitation of the periodides in acid solutions was influenced b}" various 

 factors. In this work, a new iodine solution was employed and the 

 following data are not strictly comparable with those given in Table I. 

 In every precipitation the solution was made up to about 250 cubic 

 centimeters, so that the concentration of heroin was somewhat greater 

 than that of the other alkaloids. 



Table II. — Influence of the concenfration of potassium iodide in the sohttion. 



MORPHINE. 



Number 

 of exper- 

 iment. 



Grams 

 alkaloid. 



Gram KI 

 (approx- 

 imate. ) 



Grams 

 H0SO4 

 free acid- 

 ity. 



jq iodine— 



Atoms io- 

 dine per 

 molecule 

 of alka- 

 loid. 



Added. 



Used up. 



20 

 21 

 22 

 23 



0. 03971 

 0. 03971 

 0. 03971 

 0. 03971 



0.270 

 0.279 

 0.297 

 0.540 



0.2.5 

 0.25 

 0.25 

 0.25 



cc. 



14.96 

 14.96 

 14.96 

 14.96 



ce. 



1.64 



1.56 



1.23 



0.35 



1.17 

 1.12 



0.88 

 0.25 



CODEINE. 



24 



0. 3894 



0.279 



0.25 



14.96 



4.40 



3.38 



25 



0. 3894 



0.297 



0.25 



14.96 



4.21 



3.23- 



26 



0.3894 



0.540 



0.25 



14.96 



3.74 



2.87 



HEROIN. 



27 



0.05088 



0.270 



0.25 



14.96 



5.07 



3.63 



28 



0. 05088 



0.279 



0.25 



14.96 



5.01 



3.68 



20 



0. 05088 



0.297 



0.25 



14.96 



4.14 



3.00 



30 



0. 05088 



0.540 



0.25 



14.96 



3.29 



2.39 



