CRYSTALLINE CONSTITUENTS OF OPIUM. 207 



there is no statement to this effect in the paper, nor does he mention how that 

 employed for analysis was dried, so that it is impossible to ascertain how he made 

 his experiment. When heated to a higher temperature it volatilizes completely, 

 and is deposited on cooling in fine crystals. If the quantity be large, and the 

 heat carelessly applied, a trifling carbonaceous residue is left. Meconine does not 

 appear to dissolve more abundantly in the alkalies than water, and gives no com- 

 pounds with the metallic oxides. Its effect on subacetate of lead was particularly 

 examined, but no precipitate could be obtained by any mode of operating. Cou- 

 erbe states that he obtained and analysed such a precipitate ; but his description 

 of the whole reaction is extremely unsatisfactory, his two analyses differ immense- 

 ly, and there can be little doubt, that the substance he obtained was not a true 

 chemical compound, but due to some impurity contained in the meconine he em- 

 ployed. Nitric acid, chlorine, bromine, and iodine, act upon meconine with the pro- 

 duction of particular compounds, to be afterwards described. When treated in the 

 cold with concentrated sulphuric acid, it forms a colourless solution, but on gently 

 heating, a faint purple makes its appearance, which gradually increases in depth, 

 as the temperature rises, until it becomes so intense, that a stratum of a quarter of 

 an inch thick is quite opaque ; and at length, if the temperature becomes too high, 

 sulphurous acid is evolved, and the substance charred. When the purple solution 

 is diluted with water, a dark-brown precipitate is thrown down, and a brown fluid 

 obtained. The precipitate dissolves in alkalies, with a fine red colour, and appears 

 to be a true colouring matter. Exactly the same phenomena are observed when 

 opianyl is treated in the same manner. Couerbe obtained with meconine, a green 

 colour, but I have never seen this when it was pure ; although, if it be taken after 

 its first crystallization, and while still yellow, I have found it to produce a dirty 

 greenish purple colour, and Couerbe's results are no doubt to be attributed to 

 the presence of some impurity. 



The observations just made are sufficient to show that meconine and opianyl 

 are actually identical ; and if further proof be required, it is to be found in the 

 properties of the substitution products of both substances, to be immediately de- 

 scribed. It is clear, also, that the discrepancies in the characters of the former 

 substance as described by myself, and those attributed to meconine, such as its 

 melting point, precipitation of subacetate of lead and green colour with sul- 

 phuric acid, which caused me to hesitate in asserting their identity, are due to 

 erroneous observations on the part of Couerbe. 



In what follows, I propose to make use of the name of opianyl, which appears 

 much more suited to the substance than that of meconine. For some reasons, 

 perhaps, the name proposed by the original discoverer ought to be retained ; but 

 having been applied to it as an isolated substance, it must be considered as in some 

 sense as a provisional name, and ought to give way to another, which points out 

 its relation to opianic acid, and through it to narcotine, from which it can also 

 vol. xxi. part. i. 3 k 



