THE ANALYBT. 307 THE DETECTION OF ALUM IN FLOUR AND BREAD. BY F. M. AND GEORGE RIMMINQTON. Abstracted from the Pharmaceutical Journal and Franaactions. TEE authors state that hitherto the detection of adulteration of flour and bread by the addition of alum has been entirely based upon the assumption that the alumina phosphate found above a certain percentage existed as a soluble salt of alumina, or, in fact, that an addition of alum had beea-intsntionally made.308 THE ANALYBT.They first attempted the estimation of the sulphuric acid; the estimation of the ammonia or the potash appearing beyond the power of analysis. Three modes suggeeted themselves, viz., combustion, solution (elutriation), and dialysis. Combustion wa8 a failnre; solution, that is, by mixing a certain portion OP flour with a diluted solution of alcohol and filtering out the solution and rendering it clear by boiling, or the addition of acetic acid, and precipitation by chloride of barium, proved much more practicable and satisfactory, and it is strong confirmatory evidence.. The authors next state that dialysis yielded results that have given strong hope that it is to be the process of the future.Their mode of procedure is as follows :-Take 50 grams of flour and put into a litre flask 200 C.C. of rectified spirit and to this add the flour and agitate until a perfectly smooth mixture is effected, then add distilled water to make up the measure to one litre. This ia allowed to stand with occasionally shaking for twenty or thirty minutes and then poured upon a large filter.Take any proportion of the filtrate and place it in a dialyser and allow it to dialyse twelve hours ; at the expiration of that time pour out the dialysate into a beaker and put more water in the dialysing dish and continue the process for another twelve hours, and it may be ropeuted the third and fourth time until no trace of sulphuric acid is obtained.These solutions may be dealt with separately or collectively by evaporation to a small volume and the sulphnric acid precipitated by a barium salt, collec,ted and weighed. Any salt of sulphuric acid that is present in the flour must make its nppcamncc in the ditzlysate, and the 0111s problem to settle will be its proportion to the alumina found by incineration. The dialysate mag likewise be tested for alumina. Should the amoiint of sulphuric acid be small or insignificant, it must not be ascribed to alum, but to one of the constituents of the flour, and flour does contain a small quantity of this acid in some combination or other.The authors find the logwaud test most valuable and extremely delicate. They state that it is capable of detecting alum as distinctly as Marsh’s test will detect areenic, 1 part in 1,000,000.And further that there are several kinds of logwood in use, and some of these are useless for the purpose. ALUM IN BREAD, From (( rThe Echo.” SOME legislative action will have to be taken to control the vagaries of the ‘‘ Great Unpaid ” i f the Adulteration Act is really to become a living law instead of an enact- ment to be evaded.The authorities who dismissed a clear case because the inspector failed to state in the exact words of the Act that he intended to have the articles analysed may be complimented on their sharpness, but scarcely on their intelligence. The Government analysts at Somerset House have done their best to render the Acts abortive; they could not have done more if their salaries had depended on the success of their opposition; and in a recent case of flour adulteration they shine with a remarkable brilliancy.It is a diflicult thing to detect alum in bread, because the alum is changed in the chemical proceeses of fermentation and baking, and it is almost equally d a c u l t t o detect it in flour. The soil in which wheat is grown always contains alumina, the stones by whioh it is ground are repaired with cement containing thatTHE ANALYST.300 substance, and no method has yet been devised for estimating the amount of added alum which would be deemed entirely satisfactory by the magistrates. The public analyste, however, have good reasons for believing that their analyses give correct results, but they are thwarted by the negative evidence given by the Government chemists, who persistently ignore their work and adhere to the old methods. It is quite time, both in the interests of the public and tradesmen themselves, that these burning questions should be settled. At present the Adulteration Act is little better than a capzct mortwm, so far as preventing sophistication is concerned.