608 



REPORT — 1901. 



m.p. 215°, and ty the action of phosphorus pentachloride or of alcoholic hydrogen 

 chloride it yields a chlorotetraphenylajclopentcne, C^,jH.,.5Cl, in the form of colour- 

 less prisms, m.p. 181°. By heating at 180° in a sealed tube with hydriodic 

 acid and red phosphorus, tetrapheuylcyclopentenol is reduced, and yields a 

 mixture of two hydrocarbons, C.„,H,,, smd C,^„H,,,;, which can be separated by means 

 of ether, in which the former is readily and the latter sparingly soluble. C,,,Hoi 

 separates from ether as a crystalline powder, which melts with decomposition 



Ph.C=CPh 

 over yOO°. It is no doubt tetrapliemjlcyclopentene \ y OH.,. The 



Ph.CH-CIIPh/ 

 other hydrocarbon separates in the crystalline state from alcohol. It melts at 

 80'5-81°, and is apparently identical with the tetraphenylcyclopentene 

 PhOH-GHPh 



I \CHo, already prepared, in a different manner, by Wislicemis. 



PhCH-OHPh/ 



6. Some Relations between Physical Constants and Constitution in 

 Jienzenoid Amines. Part III. By W. R. Hodgkinson and 



L. LlMPACH. 



In the * Proc. Chem. Soc.,' 1893, 9, 41, we drew attention to some relationships 

 between melting-points and constitution in some amines, and a further contribu- 

 tion by Gordan and one of us on the same subject appears in ' Trans. Chem, Soc.,' 

 1901,79,1080. 



Since then a considerable number of amines, their formyl and acetyl, and other 

 derivatives have been prepared, it is believed, in as pure a state as possible, and 

 their melting-points redetermined. 



The first point noticeable is that the difference between the melting-points of 

 the formyl and acetyl derivatives of bases of the same constitution is the same or 

 very nearly so. 



If in any base a methyl group be replaced by ethyl or oxymethyl (OCH3) the 

 melting-points of the formyl and acetyl compounds change, but the differences 

 between them appear to be the same as between the formyl and acetyl derivatives 

 of the methyl compounds. 



The following will serve as instances : — 



' The constitution is expressed as in parts I. and II. on the plan 



NHCHO 



