Letts anp Buake--On Atmospheric Carbonic Anhydride. 449 
and after absorption of the atmospheric carbonic anhydride, their 
retranster, as far as possible, to the same tube, which will again be 
sealed. 
The tubes can, of course, be kept for an indefinite period, both 
before and after their contents have been thus treated, and the 
Till 
QO 
CTT TAH Vi 
i} 
\) 
=== y A 
== ies 40 c.c. V7 
lj.t ll 
U 
[ 
Hl 
f 
i 
Ul Fill 
ey 
it 
li i 
N 
IH 
Fig. 4. 
determination of the absorbed carbonic anhydride made, when 
convenient, with an aliquot portion of their contents. 
The necessary operations for the whole process will be as 
follows :— 
Filling and sealing the Tubes (fig. 4).—A tube A of the form 
shown in figure 4 is attached at its lower extremity by a piece ot 
