Tliis plaiu question comes lióme to every housekeeper. We all desire pure aud "wholesocne food, and tliis caunot be ïad with the use oí iinpure or poisonous baking powder. 'ihere can be no onger a questiou that vil the cheaper, ower grades of baking povvders contaiti eitber aluna, lime or phosphatie acid. As loath as we ruay be to aduiit so nuch Hgainst what may have been some ot our household gods, there can be no gainsaving the unanimous testitnony of the official chemists. Indeed, analysts seem to önd no baking powder entirely free trom some one of these objectiouable iugredients except the Royal, and that they report as chemically pure. We iind some of the balung powdera idvertised as pure. to contain, ander ;he tests of Professors Chandler. ilabnshaw and others, nearly twelve per cent. of linie, while otbërs are made r'roiii alum with no cream of tartar. This, we presume, accounts for their lack of leavening power as sometíales complained of by the cook. and for the bitter taste fouud in the biscuits so frequently complained of by ourselves. But aside trom the infenority of the work done by these powders, the pliysicians assure us that lime and alum taken into the system in such quantities as this are injurious. Their phyaiological etïects aie indigestión, dyspepsia. or worse evils The question aaturally arises. why do these cheap baking powder makers "use these things'i Aluin is three cents a pound. lime still cheaiier. wliile cieatn of tartar costs thirty-five or fmty. Tlie reasons for the chetuical purity of the Royal Jiaking Powder were recently gtven in the New Vork Times ir an ititeresting description of a nevv ruethod for reflning argols, or crude creaai of t arfar. It seeuis that it is only under this process that cream of tartar can be treed froni the lime natural to it and rendered chemicallv pure: that llie patent? und plant for this cost the Koyal 11. iking Powder Company about half a tnillion dollars, and that they maintain exclusive control of the rights. Trofessor McMurtrie. latechief chemïst of the Department of Agriculture, at Washington, ü. C. nwde an examination of this process, and reponed upon the results attained in the reüned creain of tartar. The following extract fiorn his report would seem to answer the question repeated at the head of this article, and whichisso frequently propounded by the housekeeper: "I have examined the creaui of tartar used by the Royal Baking Powder Company In the inanufacture of their bakinn powder, and rind it to be perfectly pure and tree trom lime inanyform. The chernical tests to whicb 1 have submitted the Royal Bakiug Powder prove it perfectly healthful and tree hom every deletenous substauce. The Royal liaking Powder is purest in quality and highest in strength of any bakir.g powder of wlnch I have knowledge."'