1836.] On the preparation of Opium for the China market. 177 



opium. It consists in the exhaustion of the opium with water under 

 the temperature of 90° ; concentration of the solution at a low temper- 

 ature ; precipitation by slight excess of ammonia ; elutriation of the 

 precipitate with cold water ; exsiccation of it at a temperature below 

 212°, and reduction to powder; solution in cold water by muriatic 

 acid, slowly added in slight excess ; filtration and concentration to the 

 consistence of syrup ; after which, the preparation on cooling, becomes 

 a mass of crystals of muriate of morphia, moistened with a dark-colour- 

 ed solution of uncrystallizable muriate of narcotine and resinoid 

 colouring matter. This solution is abstracted from the crystals by 

 strong pressure between folds of bibulous paper ; and the solution, 

 crystallization, and expression repeated once or twice ; after which, the 

 salt is obtained in radiated bunches of snow-white silky crystals, con- 

 taining 37 parts of muriatic acid and 322 of morphia. But for the 

 unfortunate super-abundance of narcotine, and comparative paucity of 

 obtainable morphia, in Indian opium, the manufacture of the muriate 

 on a large scale might advantageously be established, at one of the 

 Bengal agencies, for the supply of the Indian medical department with 

 this admirable preparation, the marc (?) of which would be available for 

 the manufacture of lewd. 



26. Connected with the subject of analysis is another which claims 

 some attention from the opium examiner, the accuracy and sensibility 

 of the weights and balances used in his department. Neither of them 

 should ever be allowed to be soiled with opium ; and the former should 

 occasionally be compared, to see that all weights of similar denomina- 

 tions mutually correspond within one-tenth of a grain, and that the larger 

 and smaller weights are equally accurate multiples and sub-multiples of 

 each other. The knife-edges of the balances should occasionally be shar- 

 pened, so that they may turn with as little friction as possible ; and the 

 three points of suspension, whenever deranged, should be brought into 

 a perfectly straight line, by bending the beam with the hand : if the 

 centre edges be too low, the balance will, when loaded with its proper 

 weights, be in a state of unstable equilibrium, and will cause great 

 mistakes ; and if they be too low, the balance will lose its sensibility, 

 and cannot be depended upon within pei-haps two grains. Care should 

 also be taken that the distance from centre-edges to arm-edges are 

 exactly equal ; from accidental violence, this element of accuracy is 

 very apt to be deranged, and causes great confusion when overlooked. 



27. Were all the opium brought for sale unexceptionable in quality, 

 free from pasiwd, and liable to batta on account of deficient spissitude 

 only, there would be, supposing the batta levied with tolerable accu- 

 racy, little difference at the end of the manufacturing season, between 



2 A 



