e coloring
matter in one condition only, in order to insure greater uniformity in
their quality and mode of application. This would, no doubt, be a
desirable step to take if the owners of dye and print works were more
in the habit of availing themselves of the service of competent
chemists experienced in this branch, for then they would be able to
make any extract do its full work irrespective of the state of
development of the coloring matter. Such, however, was not the case,
and it was a very common thing for the consumer of dyewood extracts to
require the manufacturer to prepare them specially for him so as to
suit his own dyeing recipes, or in other words to give exactly the
same shades, weight for weight, by his own method of dyeing as the
article he was in the habit of using. The manufacturer was thus often
compelled to make many different qualities of the same extract to suit
different customers. For the same reason adulterated articles were
often preferred to the pure ones. There was, perhaps, no branch of
industry in which chemical skill of a high order could be applied with
greater advantage than in dyeing, and nowhere was this fact less
recognized. Some of the processes of dyeing were exceedingly wasteful
and stood in much need of improvement. He (Mr. Siebold) knew a large
works in which a ton of logwood extract was used daily for black
dyeing only, and he might safely assert that of this enormous quantity
only a very small proportion would be fixed on the fiber, while by far
the greater proportion was utterly wasted. Such a waste could only be
prevented by a searching investigation of its causes by trained skill.
Mr. Thomson had further alluded to the color obtained with logwood or
logwood extract and wool mordanted with bichromate of potash, and
seemed to be under the impression that the color thus obtained was not
black, but blue. This was undoubtedly the case in dyeing trials
performed as tests, as these were conducted purposely with a very
small proportion of coloring matter in order to admit of a better
comparison of the resulting depth of shades. But with larger
proportions of logwood the color obtained was a fine bluish-black, and
with the addition of a small proportion of fustic or quercitron bark
to the logwood a jet black was readily produced. With regard to Mr.
Watson Smith's observation as to fractional dyeing, he (Mr. Siebold)
did not regard this method as a suitable trial for ascertaining the
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