Aggregations produced in Gases by Sudden Cooling, 759 
surrounded by liquid air, the effect now obtained was only a 
"fair shower"; this shows that, provided a sufficiently long- 
time be given, the nuclei disappear even at the temperature of 
production. 
Carbon Dioxide Nuclei. 
Table VIII. shows the rate of disappearance of C0 2 nuclei 
at 15° and 80 cms. pressure, the nuclei having been produced 
by the sublimation of C0 2 solidified by liquid air. 
Table VIII. 
Timoin "Oven "at 15°. 
Effect. 
Tinted rain-cloud. 
Rain cloud. 
Very heavy shower. 
Good shower. 
3 mins 
10 
30 
The following Table IX. shows the effect of high tempera- 
ture upon the life of these nuclei. In this case, the nucleated 
C0 2 was driven into the 
at a pressure of 55 cms, 
The showers are therefore not so dense as those given in 
Table VIII. 
Table IX. 
Time and 
Temperature in " Oven." 
Effect. 
Time and 
Temperature in " Oven." 
Effect. 
I min. at 185° \ 
\\ „ 15° j 
3 „ 185° \ 
II „ 15° J 
10 „ 185° 1 
H » 15° j 
Heavy shower. 
Fair shower. 
Very thin 
shower. 
2^ min. at 15° 
Dense shower. 
Heavy shower. 
Good shower. 
U „ 15° 
1H „ 15° 
1 
Evidently the disappearance of the C0 2 nuclei is also 
aided by high temperature. Comparing Table VIII. with 
Table VI. we see that the C0 2 nuclei are somewhat more 
persistent than air nuclei. 
V. Electrical Condition of the Nuclei. 
Experiments were made to see if the nuclei were electrically 
charged. Nucleated air produced by cooling to the tempera- 
ture of liquid air was passed into a chamber in which it could 
3E 2 
