On the Ionisation of Atmospheric Air. 



151 



Oats' sciatic nerves. 



Days after 

 section. 



Watt 



Normal 

 1—3 . 



4—6 . 



8 

 10 

 13 



25—27 

 29 



44 



100—100. 



65 -1 

 64-5 



69 -3 



68 -2 



70 7 

 71*3 



72 -1 

 72 -5 



72 6 



66 2 



Solids, 



34-9 

 35 *5 



30 -7 



31 -8 



29 -3 

 28'7 



27-9 

 27-5 



33 -8 



Percentage 

 of phos- 

 phorus in 

 solids. 



11 



0-9 



0-9 



5 

 0-3 

 0-2 



traces 



o-o 



0-0 



Condition of 

 blood. 



Condition of 

 nerves. 



ab undant. 



J" Choline abun- 



Minimal traces' ("Nerves irritable 

 of choline ; < and histologi- 

 p resent, j [ eally healthy. 



Choline more j Irritability lost ; 



degeneration be- 

 | ginning, 

 j [" Degeneration well 

 j < shown by Mar- 

 I [ chi reaction. 



("Marchi reaction 

 j j still seen, but 

 <J absorption of 

 | degenerated fat 

 I ^ has set in. 

 ; Absorption of fat 

 j practically com- 

 plete. 

 Eeturn of func- 

 tion ; nerves re- 

 generated. 



j \ dant. 



j 1 Choline 

 I [ less. 



h 

 i 



i 



disappeared. 



(C On the Ionisation of Atmospheric Air." By C. T. E, Wilson, 

 M.A., F.E.S., Fellow of Sidney Sussex College, Cambridge. 

 Beceived February 1, — Eead March 14, 1901. 



The present communication contains an account of some of the 

 results of investigations undertaken for the Meteorological Council 

 with the object of throwing light on the phenomena of atmospheric- 

 electricity. 



In a paper* containing an account of the results arrived at during 

 the earlier stages of the investigation, I described the behaviour of 

 positively and negatively charged ions as nuclei on which water vapour 

 may condense. 



The question whether free ions are likely to occur under such con- 

 ditions as would make these experimental results applicable to the 

 explanation of atmospheric phenomena was left undecided in that 

 paper. My first experiments! on condensation phenomena had, it is 

 true, proved that in ordinary dust-free moist air, a very few nuclei are 



* ' Phil. Trans.,' A., vol. 193, pp. 289-308. 

 f ' Boy. Soc. Proc.,' vol. 59, p. 338, 1896. 



