An extract, said to be innocent, sold in casks, containing from half a cwt. to five cwt. by the brewers' druggists, under the name of bittern, is composed of calcined sulphate of iron (copperas), extract of coculus indicus berries, extract of quassia, and Spanish liquorice.

It would be very easy to adduce, in support of these remarks, the testimony of numerous individuals, by whom I have been professionally engaged to examine certain mixtures, said to be perfectly innocent, which are used in very extensive manufactories of the above description. Indeed, during the long period devoted to the practice of my profession, I have had abundant reason to be convinced that a vast number of dealers, of the highest respectability, have vended to their customers articles absolutely poisonous, which they themselves considered as harmless, and which they would not have offered for sale, had they been apprised of the spurious and pernicious nature of the compounds, and of the purposes to which they were destined.

For instance, I have known cases in which brandy merchants were not aware that the substance which they frequently purchase under the delusive name of flash, for strengthening and clarifying spiritous liquors, and which is held out as consisting of burnt sugar and isinglass only, in the form of an extract, is in reality a compound of sugar, with extract of capsicum; and that to the acrid and pungent qualities of the capsicum is to be ascribed the heightened flavour of brandy and rum, when coloured with the above-mentioned matter.

In other cases the ale-brewer has been supplied with ready-ground coriander seeds, previously mixed with a portion of nux vomica and quassia, to give a bitter taste and narcotic property to the beverage.

The retail venders of mustard do not appear to be aware that mustard seed alone cannot produce, when ground, a powder of so intense and brilliant a colour as that of the common mustard of commerce. Nor would the powder of real mustard, when mixed with salt and water, without the addition of a portion of pulverised capsicum, keep for so long a time as the mustard usually offered for sale.

Many other instances of unconscious deceptions might be mentioned, which were practised by persons of upright and honourable minds.

It is a painful reflection, that the division of labour which has been so instrumental in bringing the manufactures of this country to their present flourishing state, should have also tended to conceal and facilitate the fraudulent practices in question; and that from a correspondent ramification of commerce into a multitude of distinct branches, particularly in the metropolis and the large towns of the empire, the traffic in adulterated commodities should find its way through so many circuitous channels, as to defy the most scrutinising endeavour to trace it to its source.

It is not less lamentable that the extensive application of chemistry to the useful purposes of life, should have been perverted into an auxiliary to this nefarious traffic. But, happily for the science, it may, without difficulty, be converted into a means of detecting the abuse; to effect which, very little chemical skill is required; and the course to be pursued forms the object of the following pages.

The baker asserts that he does not put alum into bread; but he is well aware that, in purchasing a certain quantity of flour, he must take a sack of sharp whites (a term given to flour contaminated with a quantity of alum), without which it would be impossible for him to produce light, white, and porous bread, from a half-spoiled material.

The wholesale mealman frequently purchases this spurious commodity, (which forms a separate branch of business in the hands of certain individuals,) in order to enable himself to sell his decayed and half-spoiled flour.