12 
DR. ANDREWS ON THE CONSTITUTION AND PROPERTIES OF OZONE. 
continuously, the plate performing about 360 revolutions per minute. It was of 
course necessary to apply very frequently a hand rubber covered with amalgam to 
the plate, and it required the cooperation of three persons to permit the work to be 
easily performed. On passing the gas through the apparatus at nearly the same rate 
as in the experiments already described, an abundant stream of ozone was obtained, 
which enabled me to institute a very exact comparison between its properties and 
those of ozone obtained by electrolysis. 
When heated in the mercurial bath, ozone prepared in this way was rapidly 
destroyed at the temperature of 237° C., which is the same temperature at which 
electrolytic ozone was also destroyed. The vapour of boiling water, in like manner, 
caused all the ozone reactions to disappear. 
The action of water at common temperatures and of alkaline solutions upon ozone 
is very remarkable. It is commonly stated that caustic potassa absorbs ozone, but 
that pure water, and solutions of lime, baryta, and ammonia, have no action upon it. 
This statement is far from being accurate. Pure water does not absorb ozone, and 
a stream of ;iir containing ozone may be passed for any length of time through water 
without producing any change in the properties of the water. I have also preserved 
ozone for several days in a stoppered vial containing a little distilled water, and 
although the vessel was agitated from time to time, the ozone did not disappear. 
On the other hand, pure water has the property of destroying a small quantity of 
ozone. If ozone, obtained by the electrolysis of water, or by the action of the elec- 
trical spark, or by means of phosphorus, be largely diluted with atmospheric air, it 
will entirely disappear, if an attempt be made to collect it in a jar inverted over 
water. The following experiment is more precise. A flask provided with a ground 
glass stopper, of the capacity of half a litre, was filled with equal volumes of water 
and atmospheric air and inverted in the pneumatic trough. The ozone in a single 
bubble of electrolytic oxygen, passed quietly through the water into this volume of 
air, could easily be detected ; but on agitating the water briskly, even four or five 
bubbles were deprived of their ozone. The same gas, agitated with twice its volume 
of lime water, or one-third of its volume of baryta water, also ceased to exhibit the 
reactions of ozone. In like manner, the action of caustic potassa is also limited. 
A strong solution of that alkali in a Liebig’s apparatus deprived one litre of electro- 
lytic oxygen of its ozone, after which the ozone passed freely through it. These 
phenomena are singular and characteristic, and are the same with ozone from what- 
ever source it is derived. 
Peroxide of manganese destroys ozone, affording an interesting example of what 
is commonly called catalytic action. The oxide of manganese does not increase in 
weight, nor is water formed. Ozone from the three sources gives the same results. 
The odour of ozone, from whatever source derived, is the same. The same remark 
applies to its property of bleaching, without producing at first an acid reaction. 
Iodide of potassium is decomposed with the formation of iodate of potassa, and 
