t,
similar to what he had described, would convey quite sufficient for any
brewery in England, as to _cocculus indicus_."

That it may be more difficult for the officers of the excise to detect
fraudulent practices in large breweries than in small ones, may be true
to a certain extent: but what eminent London porter brewer would stake
his reputation on the chance of so paltry a gain, in which he would
inevitably be at the mercy of his own man? The eleven great porter
brewers of this metropolis are persons of so high respectability, that
there is no ground for the slightest suspicion that they would attempt
any illegal practices, which they were aware could not possibly escape
detection in their extensive establishments. And let it be remembered,
that none of them have been detected for any unlawful practices,[79]
with regard to the processes of their manufacture, or the adulteration
of their beer.

METHOD OF DETECTING THE ADULTERATION OF BEER.

The detection of the adulteration of beer with deleterious vegetable
substances is beyond the reach of chemical analysis. The presence of
sulphate of iron (p. 134) may be detected by evaporating the beer to
perfect dryness, and burning away the vegetable matter obtained, by the
action of chlorate of pot-ash in a red-hot crucible. The sulphate of
iron will be left behind among the residue in the crucible, which when
dissolved in water, may be assayed, for the constituent parts of the
salt, namely, iron and sulphuric acid: for the former, by tincture of
galls, ammonia, and prussiate of potash; and for the latter, by muriate
of barytes.[80]

Beer, which has been rendered fraudulently _hard_ (see p. 148) by the
admixture of sulphuric acid, affords a white precipitate (sulphate of
barytes), by dropping into it a solution of acetate or muriate of
barytes; and this precipitate, when collected by filtering the mass, and
after having been dried, and heated red-hot for a few minutes in a
platina crucible, does not disappear by the addition of nitric, or
muriatic acid. Genuine old beer may produce a precipitate; but the
precipitate which it affords, after having been made red-hot in a
platina crucible, instantly becomes re-dissolved with effervescence by
pouring on it some pure nitric or muriatic acid; in that case the
precipitate is malate (not sulphate) of barytes, and is owing to a
portion of malic acid having been formed in the beer.

But with regard to the vegetable materials d