• Inert, irregularly shaped granules, of various refractory materials used to promote smooth boiling and retard bumping by providing numerous points for formation of small vapor bubbles
1590D33 Stones are silicon carbide; random size pieces up to 2 mm long. Black color prevents confusion with other crystalline materials such as digestion agents.
1590F18 Stones are Hengar alumina granules; size 4 mesh.
1590F33 are same, but selenized for use in Kjeldahl digestion work.
1590G21 Stones of TFE, to avoid superheating; require no neutralization prior to introduction into chemical reaction. Autoclavable; leaves no residue.
