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more if necessary. Allow the filter to dry in a moderately warm place, at a temperature 

 not exceeding 60 C. (140 F.) until its weight remains constant, then carefully transfer the 

 crystals to a tared watch-glass and weigh them. * 



Place the crystals (which are not quite pure) in an Erlenmeyer flask, add lime water (10 cc 

 for each 0.1 gm of morphine) and shake the flask at intervals during half an hour. Pass the 

 liquid through two counterpoised, rapidly acting, plainly folded filters, one within the other 

 (the triple fold of the inner filter being laid against the single fold of the outer filter), rinse 

 the flask with more lime water, and pass the washings through the filter until the filtrate, 

 after acidulating, no longer yields a precipitate with mercuric potassium iodide T. S. Press 

 the filters until nearly dry between bibulous paper and dry them to a constant weight; then 

 weigh the contents, using the outer filter as a counterpoise. Deduct the weight of the 

 insoluble matter on the filter from the weight of the impure morphine previously found. 

 The difference multiplied by 10 represents the percentage of crystallized morphine contained 

 in the opium. 



