io8 
W. J. V. OSTERHOUT 
Care should be taken not to grasp the tube A directly, since this 
may warm the gas within it. It may be convenient to attach two 
spring clothes pins (one at either end) by which it may be handled. 
The tube A is shown on a larger scale in figure 2 : it is closed by a 
rubber stopper B (which may be shaped like a meniscus, as shown in 
the figure, though this is by no means necessary). 
The tube is placed on the meter stick K, where it is held in place 
by "sash curtain hooks" H. These are pieces of metal bent at right 
-angles, with a screw thread at one end. They are turned outward 
before the tube is in place. Then they are turned inward to hold it. 
The tube can be held in any desired position by attaching to it spring 
clothes pins (/, 0) on each side of the sash curtain hooks. In conse- 
quence the tube is held firmly in place. 
We now attach the rest of the apparatus. This consists of a 
T-tube D, a tube F (which is closed at one end), and a longer tube, /. 
All of these have a diameter as large as that of A (or larger). 
They are connected by two short pieces of rubber tubing furnished 
with clamps (at C and E) and a longer piece, G (with clamp at L). 
The tube F (which should be of the same diameter as A and at least 
I inch long) is filled with 20 percent aqueous pyrogallol^ (taking care 
to exclude air), after "which it is clamped off at E and the rubber con- 
nection thoroughly rinsed before being attached to D so that no 
pvrogallol can enter D. 
The apparatus is placed on the meter stick and fastened by the 
hooks before being attached to the tube A (by means of the rubber 
tubing at C) . It is very important that the tubes A and D be firmly 
attached to the meter stick so that they can not be pulled apart, 
allowing the reagents to escape. 
A thistle tube is now placed in /, which is firmly fastened upon the 
retort stand by the clamp, P, vSO as to hang vertically. The meter 
stick with attachments is now inverted several times to make sure 
that the tubing is firmly attached to the meter stick and that all 
joints are secure. It is then hung on the retort stand in such a manner 
as to be easily detached. After opening the clamp at L we pour into 
the thistle tube 20 percent KOH until D is filled and the level appears 
5 This strength of pyrogallol will quickly (if above 15° C.) absorb at least 15 
times its volume of oxygen. Hence if F is an inch long and filled with pyrogallol 
it can easily absorb at least 15 inches of oxygen in A. Ordinarily there are less than 
8 inches of oxygen in ^. 
