PLATE XXXIII 
Fig. i.—Special container for sulphuric acid to remove water vapor from air passing 
through it' At the right is a stopper with the entrance and exit tubes, as described 
on p. 306. 
Fig. 2.—A small absorber train for removing water vapor and carbon dioxid from 
sample of residual air. An empty acid bottle is shown at the left. 
