DYES AT THEIR SOURCE.

Southland Times, Issue 1002, 12 August 1868, Page 3

DYES AT THEIR SOURCE.

Dyes, like perfumes, are often derived from the most repulsive Bources ; gas tar gives the magenta and mauve so fashionable of late ; picric acid from the same source produces orange and yellow tones. The beautiful color ultramarine was formerly made of lapis lazuli, and was far too precious an article to be used by the calico-printers, but the modern chemist, having discovered the elements of which it is made, now builds it up artificially. This is one of the most striking results of scientific kmowledge, and was probably the.first triumph of synthetical chemistry. The costly pigment, that we treasured up, is now made artificially at Is per pound ! The method of applying it to cloth is very ingenious. As it is insoluble, how was it to be made to adhere to the material ? Chemists answered the question by mixing it with albumen, which, coagulating by heat, fixed it firmly on to the fabric to which it was applied. The waste heaps of spent madder were formerly a great nuisance, and were often thrown away, of course into those great carriers — streams, and .rj^e^STTheiice the water in th&neighborhood of dyeworks was always polluted; it- is now found that at -least one^third of this hitherto waste product can be saved by bein^ treated with a hot j »cid., Prussian blue is made from pieces of horsehoof* or refuse woolen materials, by fusion with iron and alkali. A few. years ago the scientific world was startled by the announcement that means had been arrived at of extracting the green coloring malifer' T fcriloTdpriyHJ T fromr' grassy,) leaves, &c. To utilise the. bloom of spring was indeed a daring idea, and by no means impoßsiblQ*o£' accomplishment ; . bufc ,thai excellent .feas . been bafflecL by the extreme alterabiliiiy of ' the color in in question. — Quarterly Beview