aat or _suncheepaat_ is the thread of a species of
spiral (_Corchorus olitarius_), sold under the name of jute tissues.

The cotton tissues lose about twenty-five per cent. of their weight in
bleaching, five per cent. of the substances are dissolved through
alkalies, and the other twenty per cent., which are not attacked
directly through the alkalies, are removed through chlorine, acids,
and the water itself. The linen and hemp tissues contain eighteen per
cent. of substances which are soluble in alkalies, and they lose from
twenty-seven to thirty per cent. of their weight when taken through
the consecutive bleaching operations.

The substances do not alone include the substances contained in the
fabric originally, but also such as are deposited in the preliminary
treatment of the fabrics, as dirt from the hands of the operator, and
gluten soluble in warm water; as also glue or gelatine, potash or
soda, starch, albumen, and sugar, used by weavers, etc., and which are
all soluble in water; further, such as greasy matters, calcareous
soap, coppery soap, resinous or gummo-resinous matters, and the yellow
and green coloring matters contained in textile fabrics, which are
soluble in caustic soda; and finally, the earthy constituents which
are soluble in acids.

The nature and composition of silk and wool is diametrically opposed
to that of the former. The silk is more of a gummy nature, and is
susceptible to decompose into a kind of gelatinous mass if specially
treated.

The yellow coloring principle in silk was found only to be contained
in a very small proportion, and consisting of several distinct bodies.

The wool contains, first, a fatty matter which is solid at an ordinary
temperature, and perfectly liquid at 60 deg. C.; secondly, a fatty matter
which is liquid at 15 deg. C.; thirdly, a fibrous substance which
essentially constitutes the wool in the strict sense of the word.

The wool at least contains three important principles, as it will be
known that the fibrous substance disengages sulphur and
hydro-sulphuric acid without losing its peculiar properties; and it,
therefore, appears probable that the sulphur entered as an element in
the composition of a body which is perfectly distinct from the fibrous
substance aforementioned.

In treating wool with nitric acid, and taking all possible precautions
to determine as accurately as possible the quantity of sulphuric acid
produced by the contents of sulphur in the