September, 1910. 



KNOWLEDGE. 



349 



becomes quite colourless at — 63° C. The change 

 in the colour intensitv of a solution of triphenyl- 

 methvl iodide when similarh' treated is barely 

 perceptible. 



This definite proof of the separate existence of 

 two different triphen\lmethvls strengthens the view 

 first put forward by Gomberg, and later by 

 Tschitschibabin, in the following words : " From the 

 quinone theory of structure we must at least 

 ascribe a quinone formula for triphen\lmethyl in 

 solution, while it seems that the hexaphenylethane 

 formula is in general warranted for the colourless 

 solid compound. In some cases a kind of 

 Tautomerisni can exist, so that the two isomers in 

 the solid state have the same structure, while in the 

 liquid and dissolved condition there is a mixture 

 of both." 



Numerous examples of the above equilibrium are 

 to be found in both inorganic and organic chemistry-. 

 e.g. : the dimolecular colourless nitroso compounds 

 and the unimolecular coloured molecules, of which 

 Bamberger's tertiar\- nitrosobutane is typical : the 

 latter in solution forms first colourless double 



molecules, which after a few minutes change into 

 the blue coloured simple molecules. 



The equilibrium of nitrogen peroxide, viz. : — 



N-. O4 : 



2N O, 



serves as an excellent illustration of the two 

 triphenvlmethyls. 



Wieland. criticising Gomberg"s molecular weight 

 determinations in which a double value for 

 triphen}lmethyl was obtained, states that the 

 experiment must have been conducted in solutions 

 whereby not more than about 5% of Schmidlin"s 

 \-ellow isomeride could have been present. In 

 naphthalene, on the other hand, where the amount 

 of the vellow unimolecular form is much larger, a 

 much lower molecular weight was found. 



In conclusion, it seems that while the final 

 solution of this interesting problem is still for the 

 future. \et every indication seems to point to the 

 result that the colourless triphenylniethyl is really 

 hexaphenvlethane. while the coloured solutions con- 

 tain the body implied by the term triphenylniethyl. 



SOLAR DISTrRlSA.XCE.S DURIXG JULY, 1910. 

 Bv FRANK C. DENNETT. 



Dlring July a decrease was again noticed in the number of 

 spot outbreaks. No dark spots were seen from the 19th until 

 the 25th. inclusive, but faculae were recorded every day with 

 the exception of the 20th. At noon on July 1st the longitude 

 of the central meridian was 203° 13'. 



No. 53 appears on this chart as it continued visible until 

 July 12th. 



No. 54. — On July 1st a penunibraless pore was seen in the 

 morning, about half-a-do^en such formed a train on the 2nd. 

 the number increasing during the day. It was less con- 

 spicuous on the 3rd. but on the 4th the leader had much 

 enlarged, and also the eastern members, but to a lesser extent. 

 Its greatest length was 33.000 miles, but it rapidly declined so 

 that only one pore remained on the 6th, when it was last seen. 



No. 55. — A solitary pore appeared on the 8th. and next 

 morning a second one had de\eloped. but only one remained 

 until the afternoon. 



No. 55a. — A pore was seen at first on the 11th. and about 

 four developed later, though not seen after the 12th. 



No. 56. — A solitary spot, the remains of No. 52. accompanied 

 by faculae, was seen on the 12th, being over 15,000 miles in 

 diameter. On the 14th the inner edge of the penumbra was 

 brightly fringed, and also on the 15th, when the umbra had 

 broken in two, then dwindled until the ISth, when last seen. 



No. 57. — -A tin\- black pore in bright faculae was noticed on 

 the 26th and 27th. On the 28th there were two pores west and 

 one east, which increased on 29th. The eastern spot was 

 largest on the 30th. forming, with other pores, a triangle with a 

 base of 33.000 miles. On the 31st the western pores were 

 almost gone, but the rear spotlet endured until August 2nd. 

 The group almost exactly covered the site of No. 54. 



No. 58. — On the 26th a group had come round, the leader 

 being of fair size. They decreased, and altered in appearance 

 ver\- quickly, disappearing entirely during the 31st. The group 

 was 30.000 miles in length. 



No. 59. — A single pore only was visible on the 28th. 

 The chart has been constructed from the observations of 

 John McHarg, .A. .\. Buss. E. E. Peacock and F. Dennett. 



DAY OF ILLY 



