22 i EbPORtS ON tHe Stat£ of sdiENcfi. 



calculated figures, the diflerences in those found and calculated for 0^1^14 

 being very large, and the errors in the ^vrong direction ; for as a rule 

 carbon is found too low and hydrogen too high and not ince versa. 

 Moreover, if any appreciable quantity of dimethyltetrahydrobenzene had 

 been present it could hardly have escaped detection, as on oxidation it 

 would have yielded /3/>dimethyladipic acid, which presents no difficulty of 

 isolation or identification. 



If the above quoted figures for dimethyldihydrobenzene (C and S) are 

 examined, it will be found that they add up to 99-57 ; and it is considered 

 most probable tliat the discrepancy is due to oxygen present in the form 

 <if traces of a niethoxy- compound. 



Another suggestion made by Harries and Antoni is that dimethyl- 



dihydrobenzene (C and S) is not a true dihydrobenzene but contains a 



trimethylene ring as represented in formula IX. Altogether apart 



from the probable incapability of existence of such a body, it may be 



/CH : CCK ,CH=C 



CMe/ \CH -> Cile.< | ^CH^ 



(IX) 



mentioned that the magnetic rotation of the hydrocarbon would have 

 at once proved the presence of a trimethylene ring, and, moreover, 

 there is now evidence that the same dimethyldih^drobenzene is produced 

 by the reduction of dichlorodiuiethyldihydrobenzene, and by the removal 

 of the elements of hydrogen bromide from dibromodimethylhexahydro- 

 benzene. 



/CH : CH. 



cMc,< \cn 



\CH,.CH'^ 



/ \ 



/Cn:CC)v /CH„.CUBr. 



CMp/ \CH CMc,< " >Ce.,. 



V'H, CCi^ \CH.,.CHBr/ ' 



This can only be explained if the substance be designated 1 : 1 -di- 

 methyl- A- -'-dihydrobenzene, and hence the possibility of a trimethylene 

 ring being present in the hydrocarbon is precluded. 



The whole question is further complicated by the fact that Harries 

 and Antoni prepared a hydrocarbon, which they believed to be 1 : 1-di- 

 methyl-A^ -^.dihydrobenzene also from dimethyldihydroresorcin as a 

 starting-point ; but, unfortunately, no information is given as to any 

 derivatives which would enable a comparison to be made with the hydro- 

 carbon ha\ing that undoubted structure described in this report ; and it 

 would appear that the present evidence is insufficient definitely to 

 establish the constitution of Harries and Antoni's hydrocarbon. The 

 single piece of evidence on which the supposed constitution of this latter 

 substance is based is oxidation, whereby oxalic, a succinic, and malonic 

 acids were obtained, none of which bodies afford any direct proof that 

 the hydrocarbon contained the (/ej^-dimethyl group. 



Nor is there any apparent reason for supposing that the elimination 

 of ammonia from the cyclic diamine would take place in one way and one 

 way only. Harries and Antoni have themselves shown that, when the 

 phosphate of diaminohexahydrobenzene (X) is submitted to dry distilla- 



