Definition of "prill" [prill]

• To flow, spurt (verb)
• A rill, a small stream (noun)
• A spinning top (noun)
• A pellet, a granule, a small bead (noun)
• Rich copper ore remaining after removal of low-grade material; a droplet of copper suspended in molten slag (noun)

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• "But in certain cases, more especially where large amounts of metallic oxides are present, the slag is not so clean, and with these the slag should be powdered, mixed with 40 grams of litharge and 4 of flour, and melted again; it is an advantage to add a small prill of say 2 or 3 milligrams of silver to the charge, as it insures a visible product in the cupellation."
• "For example, suppose a prill has been obtained which measures 12.5 divisions of the scale, and that a standard prill weighing 0.1 milligram measures"
• "The weight of the button is arrived at by comparing with the mean diameter of a _standard prill_ of gold of known weight."