IV–C–11

The purpose of this tube is to identify arsenical agents in the atmosphere.

There are three yellow bands around the section of the tube filled with brown absor-bent clay.

The tubes are similar in construction to the double yellow type and may be used in conjunction with the "Gasanzeiger" hand pump. Both ends are punctured and the tube is inserted into the pump; 100 strokes are taken, the ampoules of reagent in the tube are broken, and one more stroke the pump is taken to draw the liquid reagent into the absor-bent part of the tube. Arsenicals with the exception of arsine produce a brown or black color in the white section of the tube where the liquid reagent has been drawn in.

The tube are packed in tens in grayish-green painted metal containers measuring 2.5 x 4.7 x 0.5 inches. The slip-on cover has a 3 yellow band lenghtwise across the outside.

IV–C–11