446 APPENDIX. 



ounce and half of animal charcoal, at a temperature of 120" ; then 

 strain. Then, having washed away the charcoal, cautiously eva- 

 porate the liquors, that pure crystals may form. Into the decanted 

 liquor from which the crystals were first separated, previously 

 adding a pint of water, gradually drop a quantity of solution of 

 ammonia, sufficient to throw down all the morphia, shaking the 

 vessel occasionally. To this, when washed with distilled water, 

 add the hydrochloric acid, so that it may be saturated ; then 

 digest with two ounces of animal charcoal, and filter. Lastly, 

 all the charcoal being washed away, evaporate the liquors cau- 

 tiously, that pure crystals may form. 



Use, §-0. 



Acetum Cantharidis. Vinegar of Cantharides. — Take of pow- 

 dered cantharides two ounces, acetic acid one pint ; macerate the 

 cantharides in the acid for eight days, shaking them occasionally ; 

 then express and strain. 



Use^ ^c, — As an extemporaneous blister. 





