186 
IOWA ACADEMY OF SCIENCES. 
ing is as good a method for the accomplishing of the 
reactions as is known, and, when viewed from the com- 
mercial standpoint, has some very practical features inas- 
much as it consumes no reagents, as has been stated, 
It has been found possible to effect the reaction represented 
in equation (12) by what is technically known as a 
“ katalyctic ” reaction. Katalysis is the name of a class of 
chemical reactions which occur in the presence of some 
other chemical,, which is itself unaffected. It is supposed 
that, if given sufficient time, the reaction would take place 
without assistance, but for some unexplained reason, it is 
greatly hastened by the presence of the katalyctic. Two 
instances of these reactions have already been given — i. e., 
the union of hydrogen and acetylene or ethylene in the 
presence of platinum black: and the action of chlorine gas 
upon ethane in diffused sunlight. 
The katalyctic best adapted to aid in the union of water 
with acetylene is mercuric bromide. Mercuric chloride is 
of the same nature as mercuric bromide in rendering the 
reaction possible, but is unfitted for practical use, because 
of the fact that a part of it undergoes a reaction with the 
acetylene and is precipitated as a white, non-explosive pow- 
der, having the formula Co (HgCl) 2 . 
The method of procedure in the use of mercuric bro- 
mide is as follows: The salt is put into water in excess, it 
being only moderately soluble, and the solution heated to 
about 35°. The acetylene is then conducted into the 
solution, being liberated near the bottom of the vessel con- 
taining it, thus giving more time for reaction before it can 
reach the surface and escape. There should be some means 
by which the liquid shall be kept in constant agitation to 
prevent the insulation of the acetylene from the water by 
the acetaldehyde that is formed. As acetaldehyde volatil- 
izes at 20.8° it will leave the solution almost as rapidly as 
it is formed, especially if as high a temperature as 35° is 
maintained. The acetaldehyde vapor is now carried 
through a condenser, at about 0°, so arranged that should 
there be any free acetylene, it may escape, while the con- 
