415 



control-tiihe. (!ocU I serves foi- tilling, cooiv 2 for emptying- and 



cleaning. 



d. The iihst>ri>tiontuhes are fastened to a coppei- frame (fig. 5). 

 A.s with a view to pieversing a constant temperatnie 

 ilie size of tlie lliei'nioslat cannot be chosen at will, 

 straight absoi'ption-tiil)es (length 25 cms., width 3 cms.) 

 are more snitable than Pkttenkofer or WiNKLEK-tubes. 

 When baryta-water is chosen for combining witii CO, 

 (21 grammes of bariumhydroxyde -(- 3 grammes of barium- 

 chloride in 1 L. of water), the absorption is only complete, 

 when the air passes through 3 of those tnbes (each 

 containing IÜÜ cc. lye). Each frame of 6 tnbes therefore 

 can only sei've for two observations. The tnbes end at 

 the base in thin open pieces, which may be plugged 

 by rubber stoppers. At the top they are closed by rnbbei- 

 corks 3 cms. thick. In each cork there are three holes, 

 two of which serve for the inlet- and exhansl-lubes, 



while the Ihird, which serves for filling can be plugged by a little 



massive glass bar. The tnbes are connected with vacuum-rubber 



Fig. 4. 



Fig. 5. 



