146 GIBBS. 



current of oxygen. The ozone was removed from the oxygen by the combuatioi* 

 furnace and the gas ions were destroyed by the tube of tightly packed glass 

 wool G." After cooling in the oxygen current and standing eighteen hours, the 

 operation was repeated and the tube sealed out of the chain. 



A second tube of the same dimensions was treated in the same way, except that 

 before sealing it was opened just in front of the phosphorus pentoxide tube, the 

 oxygen current running at a fairly rapid rate, and a small piece of cleaned and 

 ignited silver foil inserted. The seal was then made several centimeters back 

 from the opening to avoid the introduction of moisture from the flame of the 

 blowpipe. One end of the tube was wrapped with tin foil for a distance of 5 

 centimeters and the pieces of silver put into this darkened pocket so that the 

 direct rays of the sun would not strike it. 



Silver foil discolors in the presence of ozone;" the test, however, is not as 

 delicate as some others. 



After four and ten days' exposure, respeetivelyj the tubes were removed 

 from the direct sunlight at 1 p. m. to obtain the maximum sun effect 

 and immediately tested for ozone. The first tv;be was cooled to produce 

 a slightly reduced pressure in the interior, so that on breaking the tip 

 beneath the surface of a sensitive potassium iodide and starch solution 

 about 2 cubic centimeters were drawn in. This solution was passed 

 repeatedly from end to end of the tube and showed no visible coloration 

 on standing in the dark, after twenty-four hours. The second tube was 

 tested by breaking the tips from both ends and washing out the gas, 

 through the small opening, by means of a stream of pure oxygen. The 

 issuing gas played against a piece of sensitive potassium iodide-starch 

 paper without producing any noticeable discoloration. The piece of 

 silver foil also was without indication of ozone. If active oxygen was 

 formed in the sunlight under the conditions described, the amount was 

 so minute that the delicate tests employed were decidedly negative. 



THE EFFECT OF OZONE, AND OXYGEN AND SUNLIGHT UPON THE METHYL. 

 ETHER OF PHENOL, ANISOLE. 



Anisole is not colored by a rapid current of ozonized oxygen bubbling 

 through it for two days at 30°, or by exposure to direct sunlight in the 

 presence of moisture and o.xygen for two months, the temperature oc- 

 casionally rising above 40°. 



ISTo special attempts were made to purify the anisole. A sample which 

 had been in this laboratory for some time was distilled once and the 

 middle fraction employed in the experiments. It remained practically 

 colorless throughout the experiments. The fixation of the labile hydrogen 

 atom of phenol prevents oxidation under the conditions of the experiment. 



"Thomson and Eutherford, Phil. Mag. (1896), 42, 392. 

 "Thiele, Ztschr. f. off. Chem. (1906), 12, 11. 



