State of rharmacy in France. 249 



The first article is " oxide de fer noir prepare a I'eau." This 

 preparation appears to be so great a favourite that two methods 

 are given for obtaining it. In the latter of these, contained in 

 the appendix, it is stated that iron filings moistened with water, 

 decompose it and give out hydrogen gas, and that protoxide of 

 iron is formed ; it is moreover stated that the action is accom- 

 panied with the extrication of heat ; these facts are mentioned 

 with too much minuteness to admit of doubt as to their correct- 

 ness, and yet it is generally understood that water at common 

 temperatures is not decomposable by iron. 



The next preparation is " oxide de fer noir prepare par I'acide 

 acetique." It is formed by decomposing sulphate of iron with 

 carbonate of soda ; equal parts are directed to be employed, 

 the precipitate obtained is to be washed, dried, and then mixed 

 with distilled vinegar. The mixture is to be put into an earthen 

 retort, and the fluid to. be distilled in a reverberatory furnace. 

 I am quite at a loss to conjecture the object of this employment 

 of the vinegar ; if, however, protoxide of iron be really obtained 

 by this process, it must be by its action, for otherwise a mixture 

 of carbonate and peroxide of iron would be formed. 



After three methods of preparing protoxide of iron, we have 

 one for forming oxide de fer brun, which is explained to be 

 sous-deuto-carbonate de fer ; now the fact is, that it is a mix- 

 ture of protocarbonate and peroxide of iron. It is procured by 

 decomposing sulphate of iron with carbonate of potash, but the 

 proportions to be employed are not given. We are afterwards 

 informed that the same substance may be formed by exposing 

 moistened iron filings to the air. Now the fact is, that, as al- 

 ready stated, the precipitate which is called merely a brown 

 oxide, is a mixture of carbonate and peroxide ; but the rust of 

 iron obtained by moistening filings, is altogether reddish per- 

 oxide. These are followed by " oxide de fer rouge." This is 

 prepared by decomposing sulphate of iron by heat. 



Muriate of iron is to be formed by dissolving iron filings 

 in muriatic acid, and evaporating the solution to dryness. It 

 is by the application of heat to be converted into permuriate, 

 for the jiurpobo of preparing la teinture 6therec alcoolisce de 



