CERTAIN ALKALOIDAL PERIODIDES. 



273 



began to lose. Since it was thought that this loss might be due to the 

 change in the equilibrium of iodine and alkaloid brought about by the 

 warm weather encountered at that time the desiccator was placed for a 

 week in cold storage. However, the result was a noticeable loss of 

 iodine in each periodide. Further exposure had little effect, although 

 codeine lost and heroin gained a small amount of iodine. It is believed 

 that the anomalies noted result from some molecular changes which 

 occur after long exposure. The periodides were found to be less soluble 

 in alcohol than those freshly precipitated from aqueous solution, and 

 the alcoholic solution, instead of having a deep red color, had a brown 

 and in one case a green tint. 



It is not possible to draw any conclusions as to the relative affinity 

 of the different alkaloids for iodine from these experiments. Different 

 amounts of alkaloid were taken and the amount of surface exposed and 

 the degree of subdivision also were not the same. Probably the mor- 

 phine crystals were the coarsest and those of codeine the finest. The 

 weight of morphine taken was 0.7359 gram, of codeine 0.5598 gram, 

 and of heroin 0.4112 gram. 



The morphine periodide was placed in a second desiccator with some 

 fresh morphine to ascertain if an equilibrium would be established. 

 This experiment gave the following result: 



Table XIII. — Equilibrium between morphine, periodide, and morphine. 



Time in 

 days. 



Morphine periodide. 



Morphine. 



Weight of 

 mor- 

 phine. 



Weight of 

 iodine. 



Atoms io- 

 dine per 

 molecule 

 of alka- 

 loid. 



Weight of 

 mor- 

 phine. 



Weight of 

 iodine. 



1 

 Atoms io- 

 dine per 

 molecule 

 of alka- 

 loid. 





Gram. 

 0.7359 

 0. 7359 

 0. 7359 

 0. 7359 

 0.7359 

 0.7359 

 0.7359 



Gram. 

 2. 5985 

 2.1208 

 1. 9426 

 1.8242 

 1.7100 

 1.6124 

 1. 5903 



7.93 

 6.47 

 5.93 

 5.57 

 5.22 

 4.92 

 «4.85 



Gram. 

 0. 7221 

 0. 7221 

 0.7221 

 0. 7221 

 0. 7221 

 0. 7221 

 0.7221 



Gram. 

 0. 0000 

 0.8004 

 1.0436 

 1.2039 

 1. 3484 

 1.4319 

 1.4389 



0.00 

 2.57 

 3.36 

 3.87 

 4.34 

 4.60 

 4.63 



6 

 13 

 21 

 38 

 72 

 86 



" Corrected = 4.64. The fact that the fresh morphine gained more iodine than the 

 periodide lost is attributed to their having been placed in a desicator previously saturated 

 with iodine. 



A series of experiments was also made with the sulphates of the 

 alkaloids. The work with heroin sulphate is not included in the fol- 

 lowing table, inasmuch as there is reason to believe that the salt con- 

 tained a small amount of free heroin. The weight of morphine sulphate 

 was 0.1192 gram, that of codeine sulphate 0.2133 gram; each was thor- 

 oughly dried at 95° and introduced in an anhydrous condition. 



