Made of borosilicate glass.A partial immersion thermometer, calibrated for 75 mm, is specified in
most methods for determination of melting points.Tubes are 100 mm long when supplied with both
ends open, so that 90 mm will remain after sealing.Tube length insures open end will extend well
above bath's surface to prevent bath liquid from entering tube.121670 meets requirements of USP XXI.Packed 100 tubes per vial.