390 Dr. Ure on Pharmaceutical Preparations of Iron, 



peroxide of iron weighed 32 grains. This existed in the ori- 

 ginal compound, partly as a tartrate, and partly as a subtar- 

 trate ; for not more than two-thirds of the original powder are 

 soluble in water. 



If one volume of the solution of the potash-tartrate (in 

 about seven times its weight of water) be mixed with one 

 volume of alcohol, sp. gr. 0.840, so as to form a proof-spirit 

 menstruum, the subtartrate of red oxide of iron immediately 

 forms, and falls in a viscid mass, and the spirituous liquid be- 

 comes nearly colourless, containing very little iron. 



Though the spirituous vehicle, prescribed in the Pharma- 

 copoeia, be weaker than proof, there can be no doubt from the 

 above experiments, that a dilute alcohol is not nearly so 

 proper a menstruum for this triple salt of iron as Madeira 

 wine, which, containing a considerable portion of acid, will 

 form a more powerful and permanent solution. 



4. Medical men have, in modern times, probably paid too 

 little attention to the state of oxidizement in which they admi- 

 nister iron. The older chemical physicians of the celebrated 

 school of Stahl, taught, and I believe justly, that, according as 

 this metal is differently prepared, it acquires powers over the 

 body of a different, and almost opposite, nature. Some pre- 

 parations were said to promote the motion of the fluids through 

 the whole system ; while others repressed or obstructed these 

 motions. The remarkable stimulant and deobstruent virtue 

 displayed by iron in the cure of chlorosis, was, at that period, 

 attributed to one of its supposed constituents, the phlogiston ; 

 as the astringent property was referred to the earthy ingre- 

 dient. When these notions, derived from " old experience," 

 are expressed in modern phraseology, we may say, that the 

 mildly exciting power of iron will be found in its metallic or 

 protoxide state ; while its acrid and constringing qualities may 

 be sought for in its peroxide, and in certain saline compounds, 

 where the acid contributes its share of the effect, as is the 

 case with the sulphate. 



In fact, it may be affirmed, that iron, like copper and 

 mercury, acquires acrimony (pathologically speaking) by per- 



