Intelligence and Miscellaneous Articles. 475 



of barytes, and the chlorine in that of chloride of silver. — Journ. de 

 Pharm. et de Chim., Aout 1850. 



PREPARATION AND ANALYSIS OF CODEIA. 

 BY DR. ANDERSON. 



This alkali was obtained, as usual, from the mother-liquor from 

 which morphia had been precipitated by ammonia. As the codeia 

 forms only a sixteenth to a thirtieth of the morphia, it is of course 

 mixed in this fluid with a corresponding quantity of muriate of am- 

 monia, which must be decomposed by potash in order to obtain it. 

 Much advantage is gained, however, by first evaporating the fluid to 

 crystallization, and expressing the crystals deposited, as in this way 

 the greater part of the muriate of ammonia, which is the more soluble 

 salt of the two, is left in solution ; and by repeating the crystalliza- 

 tion many times, it may be entirely removed, and crystals obtained 

 which are pure hydrochlorate of codeia. For the preparation of 

 codeia, however, it would be worse than useless to carry the process 

 thus far, as the solubility of hydrochlorate of codeia and ammonia 

 differs so little, that much of the former salt would be lost ; but by 

 carrying it a certain length, the greater part of the sal-ammoniac 

 may be separated without any material loss of codeia, and the sub- 

 sequent steps of the process much facilitated. The crystals so ob- 

 tained being dissolved in boiling water, strong solution of caustic 

 potash is added in excess., when codeia is in part precipitated as an 

 oil, which by-and-by concretes into a solid mass, and is partly de- 

 posited in crystals as the solution cools. By evaporating the fluid, 

 another crop of crystals is obtained ; and finally, when the mother- 

 liquor has been concentrated to a very small bulk, it becomes filled 

 on cooling with long silky needles of morphia, which has been re- 

 tained in solution by the excess of potash. A certain quantity of 

 morphia appears always to remain in solution along with the codeia, 

 but its quantity seems to vary considerably. Its presence in this 

 solution has been observed before, and it has been stated that it 

 exists in the form of a double salt with codeia ; Dr. Anderson states, 

 however, that this is not consistent with his experience ; at least the 

 salt separated from the muriate of ammonia by successive crystalli- 

 zations contained no morphia, but, as has been already stated, was 

 pure hydrochlorate of codeia. 



The crystals of codeia precipitated by potash in the manner de- 

 scribed, are always more or less coloured. They are purified by 

 solution in hydrochloric acid, boiling with animal charcoal, and re- 

 precipitation with a slight excess of potash, and the precipitate ob- 

 tained finally dissolved in aether to separate any morphia which may 

 adhere to it. For this purpose hydrous sether is best adapted ; and 

 it ought to be free from alcohol, as if any be present, the sether eva- 

 porates and a syrupy fluid is left behind, which refuses to crystallize. 

 When the sether is anhydrous, it dissolves the codeia with much 

 greater difficulty ; and by evaporation small crystals are deposited, 

 which are anhydrous. 



