is of no avail; the mischief has been done and no persalt remains for it to act upon. If, however, previous to the addition of the acid, a few drops of liquor potassæ be stirred into the syrup, the colour disappears almost immediately, and, the acid being in slight excess, will not again return.

Thus I found by experiment that when to half a fluid ounce of syrup discoloured by one drop of liquor ferri perchloridi, I added enough of liquor potassa (the amount would vary according to the acidity of the syrup) to produce a distinct greenish coloration, the further addition of two drops of dilute phosphoric acid restored the syrup to its original tint.

The use of hyposulphite for this purpose is of course well known, but its employment is in my opinion not so recommendable as that I have just described.

The paper will, I fear, be regarded as simply hateful and utterly unorthodox by the few; but the many will, I hope, not be displeased to learn how of two evils to choose the less.

The PRESIDENT said the thanks of the Conference were due to Mr. Groves for this paper, which was interesting pharmaceutically to them all. There were two very important points in it,—one the decoloration of the colored syrup, and the other the question of the purity of sugar. The latter had no doubt presented itself to all pharmacists who had endeavoured to obtain pure sugar.

Mr. UMNEY said that from 70 to 80 per cent. of the sugar of commerce at the present day was beet sucrose, and such would not do for the manufacture of syrup of iodide of iron, so far as his experience went. He had seen a syrup made from this sugar, even when it had been brought most accurately to the proper specific gravity, become after a time perfectly solid. He had compared it with syrup made in exactly the same way from English refined cane sucrose, and the same result did not take place. He had not had an opportunity of investigating whether this was due to the presence of inverted sugar in the beet sucrose, but perhaps some one could throw some light upon the question.

Mr. HUGHES said he used Martineau's sugar in making all his

syrups.

Mr. ANDREWS could quite corroborate what Mr. Umney said. He had had a great deal of trouble with various syrups, and particularly with syrup of the phosphates and Easton's syrup, from discoloration. He had, in fact, commenced a series of experiments on the subject, intending to communicate the results to that meeting,

but pressure of other business, public and private, had prevented his completing the investigation. He felt sure, however, that such a paper would be most valuable. He had adopted the plan of procuring his sugar from one of the large lozenge houses in London, for he could not get it pure from the neighbouring grocers, and by getting better sugar his results were much more favourable.

Mr. NAYLOR said he had noticed latterly amongst the sugar which had come into the market, especially American sugar, that it contained an appreciable quantity of sulphur; and when a syrup had been made containing acid salts, such as hypophosphites or phosphorous acid, where the phosphorous acid was somewhat in excess, after a time the syrup had become turbid and had given off sulphuretted hydrogen. He had not estimated the quantity, but it was quite sufficient to be detected by the smell, and of course it could be readily detected by the ordinary tests, such as acetate of lead. There appeared to him to be very considerable difficulty in obtaining pure cane sugar. There was a difficulty in getting any quantity of Martineau's sugar, according to his experience, but he should like to know the opinion of those who were in the habit of buying large quantities. With reference to the manufacture of iodide of iron. he was scarcely prepared to say that he was dissatisfied with the Pharmacopoeia process, but at the same time he believed that manufacturers did not adhere strictly to the directions given. One defect in the process was that the mixture was ordered to be boiled to effect the combination of the iodide and iron. According to his experience there was no such necessity. Again, if the solution were filtered, and the filtrate washed with cold water, a basic iron salt would be thrown down, and it would be quite impossible to keep that liquor so that it would retain its colour. In fact it would begin to show signs of decomposition in half an hour. But if the iodide of iron had not been boiled, and if there were an excess of iron, which appeared to influence it to some extent, the liquor could be kept for some few hours. If no wash water were used, it would not throw down a basic compound of iron. Of course it would not keep for an indefinite time; but for a reasonable time it would show no change.

Dr. SYMES said the subject of keeping syrup of iodide of iron had been a matter of discussion in the Pharmaceutical Journal and other papers connected with chemistry and pharmacy almost as long as he could remember. Mr. Groves mentioned a druggist searching his cupboard for this preparation and finding it discoloured; but he should say the cupboard was about the last place

in which to keep it. If it were filled into small bottles, and these put in a strong light, it would keep much better. He had met with samples which had readily become decolorized by being treated in the way mentioned, but on the other hand he had met with specimens which entirely resisted such efforts. It remained even yet a problem what caused the discoloration. He scarcely thought it was free iodine, but believed it was a case of oxidation. The subject, however, of most interest, was probably that of the sugar, which some few years ago he had dealt with, though not perhaps so fully as it deserved, and he was not then so thoroughly aware as he was now of one common impurity in sugar. If he remembered rightly, he then pointed out that if beet sugar were properly treated it could be made almost as pure as cane sugar. For instance, Say's sugar was regarded by some the best to use, and that was entirely from beet; it was the best refined French sugar. The American granulated sugar which he then mentioned he had since used, and found it to be probably the purest; and it was reliable as being cane sugar, and certainly had not to undergo the same treatment as beet sugar had. The fact was, crude cane sugar required much less manipulation than beet sugar to arrive at a state of purity, and consequently there would appear to be more stability about it. The greatest difficulty in the present day, was not the small quantity of glucose which might exist, so much as the presence of sulphur, which arose from the use of ultramarine to make yellowish sugars more white. If a moist crystal of citric acid were wrapped up in a sheet of blue writing paper, and held in a warm hand, it would smell of sulphuretted hydrogen. He had observed this when using such paper to wrap up chemicals, and Mr. Tanner had also noticed it quite independently. Precisely the same thing occurred in a great deal of refined sugar, which was rendered white by the use of ultramarine. He happened unfortunately to have a cask of German granulated sugar, made to look like the American, because that had obtained a reputation as a pure article, and if he made a syrup from it, there would be a decidedly blue scum on the surface. He thought pharmacists should insist on having pure sugar, and if there were a sufficient protest made against this kind of adulteration some good might be done. He did not see why public analysts should not take it up with far greater benefit than many of the matters which they now turned their attention to, and it would go far to remedy the evil they were especially considering.

Mr. ELLINOR said that some years ago he made some syrup of iodide of iron with sugar obtained from a grocer which turned colour,

and almost solidified, and neither boiling nor anything else could restore the colour. He asked the grocer what kind of sugar it was, and was told it was the best French sugar. He therefore concluded that it was some adulteration which caused the change of colour.

Professor ATTFIELD suggested that Mr. Andrews or some one else might follow up the subject he had alluded to, and make experiments on the solubility of cane sugar as distinguished from beet sugar. He had an impression that these two sugars, even when absolutely pure, did differ somewhat, though a chemist, que a chemist, might not be able to say how. Possibly if some physical experiments were made, it would be found that they were only isomeric with each other, not identical.

Mr. ANDREWS, who was understood to consent, said he knew it was a fact that they differed in solubility.

Professor ATTFIELD said Mr. Groves raised the question why syrup of iodide of iron was not discoloured when a little potash or soda was added, and had suggested that it might have something to do with the ferric compound being kept in solution by the sugar. The salt which would ordinarily be precipitated by an alkali no doubt would be kept in solution by the sugar. The fact was there probably was a persalt of iron present; though what that persalt might be he did not know. It might be ferric saccharate; but there was possibly a persalt of iron which, on the addition of alkali, and not until then, was reduced to a ferrous salt with the liberation of iodine, just as perchloride or persulphate would be; and so long as that were so a few drops of solution of alkali would not suffice for removal of free iodine. But the author's method was a better and shorter mode of dealing with the difficulty.

and

Mr. CLARK asked if Professor Attfield had ever tried the large crystals of sugar such as were introduced by Finzel, of Bristol; because he believed that all English refiners now used beet sugar, but these large crystals could not be made except from cane sugar. This sugar had only been boiled down once from the sugar cane, it gave these large crystals. He feared that they would see no more of the granulated American sugar which Dr. Symes had referred to, as the process had been patented in England, so that it could not now be imported.

Dr. SYMES said thousands of tons of the large crystal sugar were made in Liverpool containing beet sugar. There was danger of a slight impurity there in the form of lime, because he believed it was made by a patent process by which the sugar was converted into sucrate of lime.

Mr. SAVAGE, referring to Dr. Symes's remark that the syrup retained its colour if exposed to a strong light, wished to ask if it would not deteriorate by continued exposure,

Mr. FLETCHER said an interesting paper on this subject, written, he believed, by Mr. Creuse, had appeared some time since in the American Journal of Pharmacy. The author pointed out that in discoloured syrup of iodide of iron there were always two substances present, viz., grape sugar and hydriodic acid. He observed that the discoloration never went beyond a certain point, namely, that which had been called golden-sherry colour, and there it remained. It was also proved by a number of interesting experiments, that if for one-third of the cane sugar, grape sugar were substituted, this discoloration never took place. These results were strikingly confirmed by Mr. Groves's experiments, because it was very clear that on boiling a somewhat diluted syrup, the hydriodic acid present would convert a portion of the cane sugar into grape sugar, and then the discoloration stopped. It was possible also that a strong light would exert a similar influence.

The Conference then adjourned for luncheon.

On reassembling, the first paper that was read was on

THE DETECTION OF AMORPHOUS QUININE (CHINIOIDIN) IN THE FERRI ET QUINIE CITRAS, B.P.

BY DR. J. E. DE VRIJ.

During my visit to London in May last, one of my pharmaceutical friends asked me if I knew a method to detect the adulteration of this medicine by substituting partly the quiuia by the (so-called) amorphous quinine. After some reflection I replied affirmatively, and as my friend told me that he had reason to suspect that this fraud was often put into practice, the publication of my process may perhaps be useful.

The test of the B.P. for this preparation is the following:

"Fifty grains dissolved in a fluid ounce of water and treated with a slight excess of ammonia give a white precipitate, which, when collected on a filter and dried, weighs 8 grains. The precipitate is almost entirely soluble in pure ether, and when burned leaves but a minute residue."

As the pure amorphous quinine is easily soluble in ether, it is clear that, notwithstanding the quinia is partly substituted by