454 Analyses of Books. [June, 



a mixture of muriate of ammonia and subcarbonate of iron ; the 

 consequence of which was, that until the carbonic had combined 

 with a considerable portion of the ammonia of the muriate, 

 and formed carbonate of ammonia, no ferrum ammoniatum could 

 be obtained, and then only after considerable waste. 



Instead of directing a mixture of muriate of ammonia and 

 carbonate of iron to be subjected to sublimation, the College have 

 now ordered the carbonate of iron to be mixed with muriatic 

 acid, and the substance remaining after evaporation to dryness, 

 to be mixed with muriate of ammonia, and then submited to 

 sublimation. It so happens, however, that the muriatic acid 

 dissolves scarcely more than one-third of the subcarbonate of 

 iron; so that waste appears to be incurred. Indeed the better 

 and more obvious process for procuring this medicine is simply to 

 boil down a mixed solution of muriate of ammonia and permu- 

 riate of iron to dryness. By this a preparation of uniform strength 

 and unquestionable efficacy would be obtained ; and those prac- 

 titioners would be gratified who are of opinion that muriate of 

 ammonia is a useful adjunct to permuriate of iron. 



In preparing the ferri subearbonas, the College still continue 

 the wasteful process of directing nearly one-half more sulphate 

 of iron to be used than the subcarbonate of soda is capable of 

 decomposing. No excuse can be offered for this, since it had 

 been pointed out for correction. Six parts of subcarbonate of 

 soda only are directed to be used with eight parts of sulphate of 

 iron, of which they can decompose only about 5*4 parts. It is 

 indeed true that sulphate of iron is a cheap material, but the 

 chemist should have the opportunity of using it to the best 

 advantage, and errors of this description furnish those who are 

 inclined to neglect the directions of the College in other 

 respects with too plausible a pretext for so doing. 



Ferrum tartarizatum, the preparation next to be noticed, has 

 been much improved by the alterations which the College have 

 introduced. Instead of ordering the whole mass to be dried, 

 and which contained a considerable quantity of iron unacted 

 upon, the soluble portion only is directed to be used, and the 

 aqueous solution of it evaporated to dryness constitutes ferrum 

 tartarizatum. There is, however, one part of the process now 

 introduced which is perfectly useless — 1 allude to the directions 

 for boiling the metal in the solution of tartarized iron towards the 

 end of the process. No effect can surely be hoped to be pro- 

 duced by ebullition for fifteen minutes, after twenty days' expo- 

 sure to the air have ceased to cause any action. 



Vinum ferri still retains its title, although deprived of any just 

 claim to it by the substitution of dilute spirit for wine ; I was at 

 one time apprehensive indeed that it would contain neither wine 

 nor iron. The directions for preparing it are to form tartarized 

 iron with considerable excess of tartar; this being probably 

 inteuded to supply the slight acidity which wine usually pos- 



