A plaster cast of the type is, when dry, saturated with shellac varnish and redried.
By boiling this varnish with dilute nitric acid vapours of acrolein are given off, and the substance gradually becomes a solid non-adhesive mass the same as the ultimate oxidation product of both raw and boiled oil.
In varnish manufacture; it is also used for a fuel; a purer product is extensively used in the colour and fine chemical industries.
The cables are wrapped in cotton duck soaked in oxidized oil and varnish, and are sheathed in sheet iron.
Among the other important manufactures in 1905 were: chemicals, valued at $3,964,726; slaughtering and meat packing, $2,933,877; varnish, $2,893,305; stamped ware, $2,689,766; enamelled goods, $2,361,350; boots and shoes, $2,382,051; reduction of gold and silver, not from ore, $2,361,350; corsets, $2,081,761; paints, $1,812,463; silverware and silver-smithing, $1,780,906; tobacco, cigars and cigarettes, $1,742,862; hardware, $ 1, 6 16, 755; buttons, $1,281,528, and saddlery hardware, $1,151,789.