112 =—«S.. W. Johnson on-estimation of Carbonic Acid. 
wide mouth which is closed 8 a soft rubber stopper, through 
which there passes, on the one hand, 
a chlorid ot calcium tube, a lower 
bulb of which contains cotton, and, on 
the other, the neck of a vessel which con- 
tains the dilute acid. This acid reser- 
voir is so constructed that on suitably in- 
clining it, its contents will flow freely into 
the flask. For this purpose the tube 
connecting with the latter has an inter- 
nal diameter of seven millimeters, and 
its extremity is cut off obliquely; at its 
other end, the acid reservoir terminates 
in an upturned narrow tube, 6. . This 
and the upper termination of the CaCl 
tube are chosen of such diameter that 
they fit quite aly into short, narrow 
and thick-walled rubber connecters 
4 
0 a 
—_ 
oO 
ong 
oo 
ne 
&@ 
ea 
0g 
a 
bee 
5 
ie 
- 
°o 
< 
— 
Q. 
i4°) 
Qu 
cI 
o 
a 
(0 jo} 
HH 
2 
m 
t 
ys | 
=) 
Ru 
a 
SS 
stoppers ; all these joints must be gas- 
tight. In the figure the apparatus is_ 
represented in one-third its proper dimens 
The weighed substance, in case of pe One of lime, e. g., 
is placed at the bottom of the flask, most conveniently in the 
rm of small fragments, The acid vessel is nearly filled with 
Behar wait acid of s sp. gr. ll. It and the CaCl tube are 
joints are sufliciently pe 
least fifteen minutes. 
