The industries of Bonhill centre in the calico printing, dyeing and bleaching which find their headquarters in the valley.
It is employed for fire-works, for some descriptions of explosives, for safety matches and as an oxidizer in some operations, especially in dyeing and tissue printing.
Hemp yarns are also used in certain classes of carpets, for special bags for use in cop dyeing and for similar special purposes, but for the ordinary bagging and sacking the employment of hemp yarns has been almost entirely supplanted by yarns made from the jute fibre.
The more important industries comprise cotton manufactures, iron works, boat-building, dyeing and bleaching, tanning, rope-making and salt-making.
In 1760 the manufacture of silk was introduced, and dyeing with Turkey-red in 1780; but it was not till the end of the century that its industries developed into importance under the influence of Napoleon's continental system, which barred out British competition.
The presence of a bed of lignite in the neighbourhood has encouraged the industrial development of Teplitz, which carries on manufactures of machinery and metal goods, cotton and woollen goods, chemicals, hardware, sugar, dyeing and calicoprinting.
The salt is used as a mordant in dyeing and calico-printing.
One of their objects was the collection of murex, of which an enormous supply was needed for the dyeing industry; specially famous was the purple of the Laconian waters, the isles of Elishah of Ezek.
The silk of the eria or castor-oil worm (Attacus ricini) presents the same difficulties in dyeing as the common tussur.
Perth has long been famous for its dyeing and bleaching, the bleach-fields being mostly situated outside of the city, in convenient proximity to the Tay and Almond.