440 THE BRITISH PHARMACOPOEIA. 



MEMOKANDA ON SOME FORMULAE IN THE BRITISH 

 PHAKMACOPCEIA. 



(Vorschriften der Brit. Pharm.) 



1865. J N the formula for preparing Mistura Ferri composita, a few 

 small alterations suggested by experience appear worthy of 

 notice, and although attention has already been drawn to one 

 of them, the moment seems opportune for again referring to 

 the subject. 



Myrrh in The tirst point I would notice is the Myrrh, which (as often 

 stated,) should not be in povider, as the long desiccation required 

 for reducing it to that state deprives it of much of its aroma. 

 A piece of fine lump myrrh answers better ; there is, moreover, 

 an advantage by allowing the myrrh to soften by contact with 

 the water during some hours, before the emulsion is completed. 

 This emulsion is usually kept ready prepared, the sulphate of 

 iron being added when the mixture is required to be sent out. 

 As no chemist would probably prepare for stock less than a pint 

 of it, I would adapt the formula to that quantity. According 

 to the British Pharmacopoeia, each fluid ounce of the emulsion 

 requires 3J grains of sulphate of iron : it would be rather more 

 convenient to reduce this proportion to 3J grains to the ounce, 

 the mixture of the London Pharmacopoeia being 2J grains. 

 With these changes, the following would be the formula for 



Mistura Ferri MISTURA FERUI COMPOSITA. 



composita. 



1)L Ferri sulphat. grs. 70. 

 Potass, carb. grs. 60. 

 Myrrhse, 



Sacch. aa drms. 2J. 

 Sp. myrist. fl. drms. 2J-. 

 Aq. rosse, q.s 



Triturate the myrrh and carbonate of potash with the sugar and 

 sufficient rose-water to form a thin paste. Set this aside for 

 twelve hours ; then continue the trituration, gradually adding 

 rose-water and the spirit of nutmeg, so as to form 20 fluid ounces 





