1907-8.] Combustion Analysis. 709 
of the combustion, when the whole tube is heated, it also may be provided 
with a flame-spreader. 
The copper oxide employed is coarsely powdered and sifted free from 
fine dust, which during the combustion might clog and stop the tube. The 
combustion is carried out in a current of oxygen, and the calcium chloride 
and soda lime absorption tubes are always weighed filled with the same gas. 
The method adopted for mixing the substance with copper oxide, and 
transferring it to the combustion tube, is a slight modification of that used 
Fig. 1. 
by Professor Thiele of Munich. The copper oxide after ignition is trans- 
ferred while still hot to a tube A, fig. 2, which is then closed with a stopper, 
through which passes a calcium chloride tube to protect the copper oxide 
from atmospheric moisture. If the substance to be analysed is a solid, it is 
weighed off* in a small stoppered bottle B, fig. 2, the neck of which fits into 
) 
Fig. 2. 
the constriction of A, so that the substance may be mixed in B with a 
quantity of copper oxide from A, with as little exposure to the atmosphere 
as possible. The end of the combustion tube fits into the wider part of A, 
so that it also may be conveniently charged with copper oxide from the 
ignited supply. After the combustion tube has received its charge of 
copper oxide, the mixture of substance and copper oxide is transferred from 
B into the combustion tube, the neck of the stoppered bottle being of such 
a diameter as to fit inside the end of the latter. The bottle is then “ washed 
out” once or twice with copper oxide, received as before from A, and 
