hillebranp.] WATER HYGROSCOPIC, ZEOLITIO, CRYSTAL. 
37 
heat of a lamp in order to expel t ho water retained ai 300 to 350 (\ 
To facilitate this removal the stand is on rollers, so that after clamp- 
ing the projecting end of the tube and removing the front of the 
box F and the little side pieces S closing the horizontal slits, the oven 
can be rolled bodily backward, leaving the tube and its attachment- in 
their original position, ready for further heating over a burner or 
blast. The removable front F of the oven i> made of two pieces of 
sheet asbestos board stiffened by an interlaid piece of sheet copper. 
The inner oiece i^f asbestos board tits snugly into the box, while the 
i 
I 
-c^r-sra* 
> 
a 
Fig. 3.— Chatard's form of drying oven for water determinations. B, copper box. 18cm. long. lO.k-ni. 
high, 9cm. wide, open in front, its sides and top covered with asbestos board: S, two slides of 
different si/rs to close the openingsO, after the tube is in position; F, asbestos-board front stiffened 
by an interlaid sheet of copper; R, metal rod to hold front in place: A. calcium chloride absorp- 
tion tube. 
outer one, being slightly larger, by its projecting edges hinders the 
door from falling in and helps to prevent air currents. This door is 
held in place by the metal rod 1\. The little slides S are mad.- in a some- 
what similar manner, and are intended to slip in from the front and 
close tht 4 two openings O after the tube is in place, hut before closing 
the front. 
For other forms of tubes adapted to similar determinations, see 
pages P> and !•;. 
