290 Mr. C. Tomlinson on Action of Ozone on Nuclei. [Apr. 4, 



III. " On the Action of Ozone on Nuclei." By Charles Tom- 

 linson, F.R.S. Received March 14, 1878. 



After the reading of my paper on the 21st ultimo, Professor Stokes 

 was so good as to suggest that some of my experiments should be re- 

 peated with ozone, prepared by the action of a coil, instead of that of 

 phosphorus. 



Professor Guthrie was so kind as to furnish me with a couple of 

 bottles of ozone, prepared by sending oxygen slowly through Wills's 

 generator in connexion with an induction coil. 



The ozone was used soon after it was prepared, and in the following 

 manner : — 



Oil of cajuput was distilled, and the fresh distillate was found to be 

 inactive on a supersaturated solution of sodic sulphate (3 to 1), 

 although it was repeatedly shaken up with the solution. The newly- 

 distilled oil was poured into one of the bottles of ozone, and shaken up 

 with it, and then left for about fifteen minutes. It was dropped into 

 nine flasks of the solution just named, and was active in all. In some 

 of the flasks the solution became solid as soon as the ozonised oil 

 reached the surface ; in others, immediately on shaking the flask, or 

 after a short interval of repose ; while, in a third set, after adding the 

 oil, the axis of the flask being brought into a nearly horizontal position, 

 the flask was made to revolve slowly, when the solution solidified 

 against the side, so as to form a kind of lining to it. 



On the 12th March the wind was N.E., and the ozone in the air was 

 very active on test paper. A paraffin oil of high boiling point was 

 distilled, and specimens of the fresh distillate were powerfully active 

 on a solution of sodic sulphate (2 to 1). A similar oil distilled during 

 a S. or W, wind, as noticed in a former note, was inactive. 



To a solution of sodic sulphate (3 to 1), containing oil of cajuput in 

 an inactive condition, a solution of hydric peroxide was added, but it 

 had no effect in rendering the oil active. The flask was shaken 

 every day during a week, and the only effect was to liberate bubbles of 

 gas. On adding to this flask a drop or two of the ozonised oil, the 

 solution immediately became solid. 



(23rd March.) The inactive distillates of cajuput and paraffin oils, 

 shaken up several times during about half-an-hour with pure oxygen 

 gas, became active. Test papers, suspended in the bottles, showed the 

 presence of ozone. Washed castor oil, similarly treated, remained in- 

 active ; but shaken up with ozone, and left in contact with it for some 

 hours, became active. 



I repeated the experiment, described in a former note, on the ac- 

 tivity of charcoal, on which Pellogio founds his theory of absorption. 

 Pieces of box- wood, buried in sand, were heated in a crucible during 



