TEE ANALYST. 313 CORREBPO NBENCE. [The Editors are not responsible for the opinion8 of their Correspondents.1 To THE EDITOR OF L L THE ANALYST.” SIq-Having recently examined a large number of samples of violet powder, I have been much struck by the variety of articles sold under that name, and I am inclined to ask the old question, what is violet powder ? It ia usually believed to consist of staxch, and some scenting material, e.g.orris root; but I observe that in a recent case when a dealer was prosecuted for selling violet powder, not being of the quality of the article demanded, he set up the defence that any thing not injurious, might be sold as videt powder, as there is no recognized formula for it, and this defence was considered good by the magistrate, unfortiinately the report did not say of what the powder consisted.Now it seems to me that if the powder is not of such a nature as to answer the purpose for which it is intended, it comes within the meaning of the 6th clause of the Sale of Food and Drugs Act, though it may contain nothing absolutely deleterious. The purpose m I believe for which violet powder is used, especially in the nursery, is as a desiccant, and to prevent chafing.The question, therefore is, will the articles Bold answer these purposes properly? Now, the substance I have motit frequently found in the violet powders of commerce is ground gypsum in sharp crystalline particles and fully hydrated, the quantity varying from 29 per cent. as a minimum, to 100 per cent. as a maximum; fully two thirds of the samples examined varied within these limits.How hydrated sulphate of calcium can act as a desiccant I cannot conceive, and the sharp crystalline grains would I ehould think, if applied to an irritable skin, be anything but soothing. Ought not the sale of such powder to be stopped? No one would purchase it i f they know what it was, yet it can hardly be said that gypsum is a deleterious substance, though I believe under certain circumstances it would produce deleterious effects.July, 1878. CHARLES HEISCH. Prom ths Pharmacetdical Joecnzal.” VIOLET POWDER. Sq-In common, no doubt, with other analysts, I have received a great number of samples of violet powder for analysis, and without offering an opinion as to what the composition of articlea bearing that name ought to be, I have considered it my duty to endeavour to allay any unnecessary alarm which recent lamentable accidents connected with the use of such articles have tended to produce.You have, I think, suficiently indioted in your leader last week that the term (‘ violet powder ” is applied to several preparations, differing greatly in composition, and not always used for the same purpose.I can fully confirm your statement that there are two principal varities of so-called violet powder in commerce, stareh forming the basis of one, and hydrated sulphate of calcium that of the other, while there are several sub- varieties produced by the addition of other ingredients. But while 1 admit the justness of your remarks in Borne reepeots, I cannot agree with your implied objection on merely inferencinl grounds to the use of hydrated sulphate of calcium as a dusting powder.It has been long and very extensively used, without, as I am informed, any fault having been found with it, and in cases that have comc under my immediate observation it has proved very beneficial, and in the estimation of those using it sometimes preferable even to starch, T, REDWOOD.THE ANALYST. From the u Pharmacszctical Journal.” b,-I have been connected for more than forty years, man and boy, with the retail drug trade, and have during that rather lengthened period always understood that what is called cc violet powder ” wall a composition of starch powder, orris root powder and a little perfume; the first article being about 96 per cent.of the whole. It seems, however, that I have been mistaken, and that terra alba, magnesia, etc., are the legitimate ingredients. When such an authority as Professor Redwood speaks, there is nothing left for a humble mortal like myself then to “ baiseer la t4te et croire.” DUM VIVO DISCO,