28. A. W. Wright—Production of Ozone with Electricity. 
but required a considerably longer time for the change. 
WwW chénbein’s test solution is employed the deep blue 
color is immediately produced, but the solution is too thick to 
work well if the starch has been heated considerably, or for a 
long time, in making it. A better proportion is to take one 
part of potassic iodide by weight, ten parts of starch, and five 
thousand parts of water. This forms a milky solution, suffi- 
ciently mobile to mix well when the ozonized air bubbles 
through it. When 100 cubic centimeters of this solution were 
used, and air passed through the apparatus as before, the blue 
color appeared at once on = uaptin of electricity, and in 30 
seconds it was deeply colored. 
ith dry oxygen the effects were much more rapid and re- 
markable. 100 cubic centimeters of the solution were used, 
as before. The instant the machine was put in action the 
liquid about the end of the delivery tube became deep blue, 
and in from ten to fifteen seconds the whole had acquired a 
uniform and intense blue color. 
The summer moisture having interfered somewhat with the 
effective working of the electro-machine, there has been no 
Opportunity to determine the percentage of ozone produced in 
this manner, but it appears to be very large. When dry oxy- 
gen is passed through the tube very slowly, the issuing gas 
when inhaled produces a painful burning sensation in the lungs, 
and causes violent coughing, which persists for a considerable 
me. 
When oxvgen is used it is found that the electrodes must 
be separated to a much greater distance than is necessary for 
air, otherwise x etal toe and destroy a large proportion of the 
a ormed. 
were separated about 11% centimeters. When the tube was 
filled with air and the poles were 7 or 8 centimeters apart the 
