DR. ANDREWS ON THE CONSTITUTION AND PROPERTIES OF OZONE. 
9 
The agreement is complete, and proves unequivocally that water is not a product 
of the decomposition of ozone, which therefore does not contain hydrogen as a con- 
stituent. If its composition were HO 3 , the apparatus would have increased 0T841 
grm. in weight, instead of 0'll79grm. 
The amount of ozone formed in these experiments was tolerably uniform. For 
1 litre of oxygen the following weiglits of ozone were obtained ; — 
I. 0'0038 grm. 
II. 00037 grm. 
III. 0'0046grm. 
IV. 0*0043 grm. 
V. 0*0040 grm. 
Mean . . 0*0041 grm. 
In the arangement above described, the oxygen gas derived from the electrolytic 
decomposition of water was therefore accmpanied by about a-g^th of its weight of 
ozone. 
In order to remove every possible doubt from these results, I fitted up an apparatus 
from every part of which organic substances were excluded. No diaphragm was 
used, and all the connexions were made, either by fusing the ends of the connecting 
tubes together, or by means of ground glass joints. The arrangement is represented 
in fig. 2 . Two platina wires (fig. 3) were fused into the end of a glass tube, which 
was fitted by grinding to the tubulated neck h of the vessel A. The tube BB'B" was 
connected at a with the vessel A by a ground joint, and with C by fusion. It con- 
tained pumice moistened with sulphuric acid. The vessel C was also filled with 
sulphuric acid, and was connected by a ground glass joint with the iodide of potas- 
sium vessel D. The vessel E contained, as before, sulphuric acid. In this experi- 
ment, both the hydrogen and the oxygen traversed the apparatus, the accuracy of 
which was thus exposed to a very severe test. 
Twenty-two litres of the mixed gases were passed through the apparatus. The 
gain in weight of D and E was 0*0135 grm., the respective heights of the barometer 
at the first and second weighings having been 28*96 in. and 29*57 in*? and the tempe- 
ratures 1]°*1 and 10 °* 0 . The correction for change of pressure and temperature is 
therefore 4-0*0014 grm., and the true gain 
0*0149 grm. 
The free iodine in D, due to the action of the ozone, neutralized 62*65 measures of a 
solution of sulphurous acid, of which 1 measure corresponded to 0*00373 grm. iodine. 
The weight of ozone deduced from the iodine set free is therefore 
0*0148 grm. 
The identity of these results is very satisfactory, when it is considered that this 
small weight of ozone was separated from 22 litres, or nearly five gallon measures of 
MDCCCLVI. 
c 
