ON HYDROCHLORATE OF MORPHIA. 
159 
change which is immediately effected by adding to the solu- 
tion of sulphate of morphia a saturated solution of chloride of 
barium, as long as any precipitate is formed. In this case a 
decomposition of water takes place ; the oxygen of which 
converts the barium into baryta, which unites with the sul- 
phuric acid, whilst the hydrogen, uniting with the chlorine, 
forms hydrochloric acid, to unite with the morphia. An in- 
soluble sulphate of baryta is thrown down, and the soluble 
hydrochlorate of morphia remains in solution, which, with 
the addition of the washings of the precipitate, is evaporated 
to crystallization in a water-bath ; and affords, by pressure, a 
brown crystallized mass. The expressed fluid, diluted with 
an equal quantity of distilled water is again, and a second 
time, submitted to evaporation and expression, until it ceases 
to afford more crystals. 
3. The whole of the crystals are next to be re-dissolved, 
and digested with animal charcoal ; then strained in conjunc- 
tion with the washings of the charcoal, and the liquors evapo- 
rated to crystallization. The crystals obtained by this second 
crystallization are sufficiently pure for medicinal use : but in 
order to obtain them in the highest state of purity, they should 
be again re-dissolved, and the crystals then procured should be 
only slightly pressed. 
The hydrochlorate of morphia, obtained by this process, is 
in silky, plumose, acicular, snow-white crystals, forming a 
colorless limpid solution, with distilled water, at 60° ; and a 
saturated solution in water, at 212°, congeals into a crystalline 
mass in cooling. 
Ibid, 
