no 



THE ALUMNI JOURNAL. 



salt found in the ash. Kebler does 

 not indicate but I think there can be 

 little doubt that the potassium would ex- 

 ist in the precipitate as the sparingly sol- 

 uble potassium-magnesium-phosphate, 

 which would be decomposed when igni- 

 ted with the organic salts. There would 

 therefore be a small error due to neutral- 

 phosphate in titrating with standard acid. 

 It is difficult to suggest a means of getting 

 rid of this trifling error, which is not 

 open to objection. The slight error due 

 to basic-calcium-meconate may be elimi- 

 nated by adding a small quantity of am- 

 monium oxalate before precipitating. By 

 this means the calcium is thrown down as 

 neutral-oxalate, which does not interfere 

 with the titration. Kebler inclines 

 to the belief, that determination of the 

 ash, after calculating the carbonate into 

 meconate, is the best means of correcting 

 for impurity in the morphine precipitate, 

 but he admits that titration with acid 

 is nearly as accurate and much more ex- 

 peditious. It is evident that in the case 

 of a precipitate containing a good deal of 

 organic impurity, estimation by standard 

 acid would be the better way ; while if 

 the precipitate contained basic mineral 

 matter it might be more accurate to cor- 

 rect by an ash determination. The idea 

 of washing the precipitated morphine 

 with lime-water is a good one, though 

 somewhat tedious. By this means the 

 alkaloid is entirely dissolved, and most 

 impurities left behind. I have used bar- 

 yta-water for the same purpose. Being 

 stronger it has a more powerful solvent 

 action on the morphine, but possibly it 

 also dissolves more coloring matter. 

 Treatment with lime-water or baryta- 

 water may sometimes be useful as a 

 check, but practically I think titration 

 with decinormal acid is the best means 

 for estimating the morphine precipitate. 



In the "Pharmaceutical Journal" I 

 have described two methods of opium 



assay, (XXII. 740 and XXIV. 874) 

 which I have since slightly modified. As 

 they appear to have some advantages, 

 they may be here briefly described. 



A. ID grms. of opium are exhausted 

 with spirit of "proof strength" (.920 sp. 

 g.). Kvaporate to one fourth volume. 

 Dilute this with half its volume of water 

 containing .05 grm. of ammonium oxa- 

 late, then cautiously neutralize with 

 ammonia so as to leave just perceptibly 

 acid. Allow to stand for an hour, filter, 

 and concentrate to 8 c. c, then transfer 

 to a flask or bottle holding 100 c. c. by 

 means of 2 c. c. water and 3 c, c. alco- 

 hol, afterwards adding 2.5 c. c. solution 

 of ammonia (.960 sp. g.) and 25 c. c. 

 ether. The flask is corked and shaken 

 occasionly during the next hour. After 

 18 hours the ether is decanted as com- 

 pletely as possible, the precipitate collect- 

 ed on counterpoised filters, washed with 

 morphiated water and dried. It is then 

 washed with chloroform and dried about 

 60° C. Finally it may be titrated with 

 standard acid. The success of this 

 method depends chiefly on the careful 

 neutralization of the solution, avoiding 

 any considerable amount of free acid on 

 the one hand, and avoiding also, on the 

 other, any precipitation of morphine- If 

 these conditions are observed, a very pure 

 precipitate is obtained, the treatment with 

 standard acid being almost superfluous. 

 This method is very suitable for the esti- 

 mation of tincture of opium. I have been 

 accustomed to use neutral litmus paper 

 as indicator in acidifying the morphine. 

 Farr and Wright recommend to add ex- 

 cess of acid, and titrate back with „ soda, 

 using methyl-orange as indicator. 



B. 10 grms. of opium are digested with 

 30 c.c. water, until all soluble matter has 

 apparently passed into solution. 1.8 

 gram, barium chloride dissolved in 10 

 c.c. water is added, the mixture diluted 

 and well stirred. It is then filtered, and 



