: nothing more is necessary than to make a solution
or infusion of the vegetable substance supposed proper for that
purpose, and that upon being mixed with a solution of glue, will show
by the greater or less quantity of precipitate produced, what
probability there is that such substance might be advantageously
employed in tanning.

_Another Remark._

Lime-water also offers an excellent means of discovering such
substances. If lime-water be added to a solution of tan, the mixture
instantly produces a copious precipitate; and if a sufficient quantity
of lime-water be added to neutralize the whole of the tanning
principle, then the supernatant liquor, although still possessing
colour, will not form any precipitate with glue; I mean in solution. In
like manner the liquor separated from a precipitation, caused by the
mixture of a solution of tan with one of glue, will not produce any
precipitate with lime-water, if, during the precipitation, the tanning
principle has been completely neutralized. This shows evidently that
Doctor M'Bride's method of exhausting the tan by means of lime-water is
defective, and that by so doing a loss of the tanning principle takes
place, in proportion to the quantity of it contained or combined with
the lime dissolved in the lime-water.

_Another Remark._

As in summer the solution of tan is disposed to run into the vinous
fermentation, and, of course, from that into the acetous, and have its
principal changed, no more of the solution of tan should be prepared in
the summer season than is wanted for immediate use. In winter, this
precaution in not necessary, as in that season it will keep, and may be
then prepared for exportation to any part of Europe and thus converted
into a profitable article of commerce.

_A table showing the time different hides took to be completed, in
the operations of preparing and tanning._

Ten ox hides, taken the 17th of August, were completely tanned by the
6th of September, in all, twenty days.

Washing the hides, 2 days.
Taking off the hair, 5 do.
Raising or swelling, 5 do.
Second washing, 2 do.
Tanning, (properly so called,) 6 do.
---------
20 days.

Ten ox hides, taken the 19th of July, were tanned the 9th of August,