It is a black amorphous powder soluble in concentrated sulphuric and hydrochloric acids, and when in the moist state readily oxidizes on exposure.
POWDER (through O.
In some birds, such as the herons, certain down-feathers or plumulae break off into a fine dust as fast as they are formed and form tracts defined in size and situation and known as "powder-down patches."
In the former he developed a valuable method for the investigation of aerial waves within pipes, based on the fact that a finely divided powder - lycopodium, for example - when dusted over the interior of a tube in which is established a vibrating column of air, tends to collect in heaps at the nodes, the distance between which can thus be ascertained.
(1617); a lunatic asylum; the Van Renswoude orphanage, the theatre, a school of design, the powder magazine and the state arsenal, originally a warehouse of the East India Company, and now used as a manufactory of artillery stores.