c.
of water is added, then two to three drops of a 15 to 20 per cent.
solution of alpha-naphthol in alcohol, and finally an excess of
concentrated sulphuric acid; on agitating, a deep violet colour is
developed. By using thymol in place of the alpha-naphthol, a
red or scarlet colour is produced. If the fibre were one of an animal
nature, merely a yellow or greenish-yellow coloured solution would
result. I told you, however, that jute is not chemically identical with
cotton and linen. The substance of its fibre has been termed "bastose"
by Cross and Bevan, who have investigated it. It is not identical with
ordinary cellulose, for if we take a little of the jute, soak it in
dilute acid, then in chloride of lime or hypochlorite of soda, and
finally pass it through a bath of sulphite of soda, a beautiful crimson
colour develops upon it, not developed in the case of cellulose (cotton,
linen, etc.). It is certain that it is a kind of cellulose, but still
not identical with true cellulose. All animal fibres, when burnt, emit a
peculiar empyreumatic odour resembling that from burnt feathers, an
odour which no vegetable fibre under like circumstances emits.
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