Dr. Ure on Opium and Us Testa. 59 



spirit, to extract the narcotine and resin, and then with strong 

 alcohol to dissolve out the morphia. The residuary meconate 

 X)f magnesia is to be digested in dilute sulphuric acid, and the 

 meconic acid is to be thrown down from that solution by 

 acetate of lead. The meconate of lead is to be washed, then 

 (diflfused in water, and decomposed by a stream of sulphuretted 

 hydrogen gas. The meconic acid is set free and dissolved, 

 and may be procured, it is said, in impure, scaly crystals, by 

 evaporation. 



On this process it may be remarked, that the sulphuric 

 iEicid of the sulphate of magnesia is unnecessarily dragged 

 along, to the injury of the meconic acid ; for sulphate of lead 

 is formed simultaneously with meconate, on adding the acetate 

 of that metal to the mixture of the magnesian sulphate and 

 meconic acid ; and these two insoluble salts, the sulphate and 

 meconate of lead, afterwards evolve their acids simultaneously 

 to the sulphuretted hydrogen gas. 



Whereas, by throwing down the meconic acid by the just 

 quantity of acidulous acetate of lead, washing the precipitate, 

 and decomposing it, either by the equivalent dose of sulphuric 

 acid or by sulphuretted hydrogen, we at once obtain a rela- 

 tively pure meconic acid. 



From the circumstance of magnesia precipitating both the 

 meconic acid and morphia from an opium solution, it may be 

 inferred, that meconic acid will form an insoluble compound 

 with magnesia. But this is by no means the case, for if we 

 heat a solution of meconic acid with magnesia in excess, no 

 meconic acid is withdrawn from the liquid, for it strikes as 

 deep a red, with permuriate of iron, as before the magnesia 

 was presented to it ; but acetate of lead separates the whole 

 of the meconic acid from solution or tincture of opium ; so 

 that the supernatant liquid occasion^ merely a faint, greenish- 

 brown colour, with red nitrate of iron. 



Among the criminal abuses of the diffusion of knowledge 

 which characterize the present times, the administration of 

 opium, or its tincture, concealed in various vehicles, by the 

 lower orders, with the most felonious purposes, holds a con- 

 spicuous place. An atrocious crime of this nature was brought 

 specially under my notice, about a year ago, in examining, by 

 desire of the magistrates of Glasgow, the conteats of the 



