PART III. PHARMACY. Dialysed Iron. M. Personne. (Journ. de Pharm. et de Chim., Oct. 1879, 332.) This preparation, though commonly announced to be a pure ferric oxide in a soluble form, always contains a considerable proportion of ferric chloride, and generally also some ferric sulphate, and is thus far from what it is represented to be. In other respects it differs from ordinary sesquioxide of iron, in being insoluble in acids and having a lower specific heat. The fact that it cannot pass through the membranes in the same manner as crystalloids, that it is precipitated by acids and saline solutions, and, above all, that it is quite insoluble in the gastric juice, induces the author to regard the preparation as medicinally inactive. Of its utter insolubility in the gastric juice he has fully satisfied himself by experiments on dogs. He also points out that when this modified form of ferric oxide was first discovered, its freedom from astringency marked it out as a valuable medicinal preparation; but on trial it was soon abandoned as worthless. Its subsequent revival and present popularity are attributed by the author to the effective wholesale and misleading advertisements. The Diffusive Properties of some Preparations of Iron. Prof. Redwood. (From a paper read before the Pharmaceutical Society, March 3rd, 1880, and printed in the Pharm. Journ., 3rd series, ix., 709-712). M. Personne's recent statement to the effect that dialysed iron is incapable of being absorbed during its passage through the intestinal canal, and therefore inactive (see the foregoing article), led the author to infer that if this inactivity be due in any measure to the colloidal state of the iron, it might be expected that other preparations of iron would, to some extent at any rate, owe their activity as medicinal agents to their diffusive properties. As the scaly preparations of iron agree with dialysed iron in their freedom from inky taste and astringency, and in their incapability of crystallizing, it might be supposed that these scaly preparations are either colloidal, like dialysed iron, or at least that they are deficient in diffusive power; for colloids are usually marked by absence or deficiency of taste. These considerations induced the author to make the diffusive power of iron preparations the subject of an experimental investigation. The dialyser used in the experiments consisted of a glass jar, the membrane-covered mouth of which was 5 inches in diameter; and this rested in the mouth of a white earthen dish. Two thousand grain measures of either a 5 per cent. or a 10 per cent. solution of the salt used were put into the glass jar, and 25 ounces of water into the dish. The diffusate was usually removed at the expiration of two, but sometimes of three days, at the commencement of an experiment, although a longer time was allowed for each separate diffusion when the action became sluggish towards the end of an experiment. The first series of experiments were made with ferric citrate obtained by saturating solution of citric acid with freshly precipitated ferric hydrate, and evaporating in the usual way. The results are given in the following tabulated statement: 200 grains of Citrate, containing 6458 grains of Fes Os in dialyser. (Residue in Dialyser.) 4.86 2.75 Percent. Fe, 0, in Residue. 56.65. Total. 136.82 61.10 Loss 63.18 3.48 200.00 64.58 The table shows an apparent loss in the process of 63.18 grains of salt, but only a loss of 348 grains of Fe, Og, the latter probably arising from adhesion to the septum. No entire cessation of diffusion was observed. The next set of experiments was made with four samples of ammonio-citrate of iron, marked 2a, 2b, 2 c, and 2 d, and containing 30-21, 30·9, 30-65, and again 30·65 per cent. of Fe, Og. Nos. 2 cand 2d were both the same sample, but the one was used in pure aqueous solution, and the other (2d) in a solution rendered strongly alkaline by ammonia. The following table shows the principal results of dialysis in these four experiments : Ten per cent. Solutions (200 grains of Ammonio-citrate of Iron in 2000 Having observed that diffusion stopped when the salt in the dialyser became highly basic, and that the diffusate as well as the contents of the dialyser became more and more basic as the process proceeded, the author next tried to ascertain whether with a salt containing less than the usual proportion of oxide of iron, the diffusion might be carried further than it was found possible to do in the preceding experiments. For this purpose he obtained a good, wellscaled, neutral, and perfectly soluble sample of ammonio-citrate of iron, containing only 2592 per cent. of Fe, O. 10 per cent. and per cent. solutions of this salt were submitted to dialysis, in the way already described, and the results obtained are given in the following tabulated statements :— 5 -- At the end of twenty-eight days, diffusion having stopped, the salt still left in the dialyser was found to contain 61 26 per cent. of |