CHEMISTRY. 447 



in the petroleiiin ether extract from Cascnra amarga and Phlox Caro- 

 lina, have discovered a solid, crystalline hydrocarbon, melting- at lOG^. 

 In composition it is represented by theformnla CuTIifj, or some mnltiple 

 thereof. (Berichte, xxi, 2598.) 



The si/nthesis of closed carbon chains. — Dnrin^!^ 18S7 and 1888, W. H. 

 Perkin, jr., has published a number of i)apers extending- his earlier 

 researches u[)on compounds containing closed carbon chains. In some 

 of these papers he appears in joint authorship with other investi- 

 gators. 



By acting- upou ethyl malonate in presence of sodium with trimethy- 

 lene bromide a number of tetramethylene derivatives were formed, but 

 the hydrocarbon itself could not be prepared. In the same reaction 

 some pentamethylene derivatives were also produced. By other pro- 

 cesses compounds involving hexa- and hepta methylene were obtained. 

 Some work was also done on triinethylene derivatives, and also on the 

 synthesis of aromatic com])Ounds having- closed carbon chains. (See 

 Perkin, Journ, Chem. Soc, li, i)p. 1, L*40, 702, 849, and ltii, 1 ; Colman 

 and Perkin, ibid., lt, 228, and liii, 185 : Freer and Perkin, ibid., li, 820, 

 and Liii, 202, 215.) The aromatic comi)oun(ls were also studied by 

 Kipping, ibid., liii, 21. None of these papers are suited for detailed 

 abstraction. 



A new general method of si/nthesis for aromatic compounds. — Friedel 

 and Crafts, continuing their researches upon the re-actions of aromatic 

 hydrocarbons in presence of aluminum chloride, find that the latter 

 re-agent causes benzene and its homologues to take up readily various 

 elements, radicles, and acid aidiydrides. Thus, when <lry oxygen is 

 passed into a mixture of benzene with aluminum chloride, it is slowly 

 absorbed; and upon ti eating the mass with water i)henol is formed. 

 Toluene, similarly treated, yields cresol. The benzene and chloride 

 mixture easily takes uj) i)0wdered snli)hur, with evolution of hydro- 

 chloric and sulphydric acids, and afterwards, with watei', gives phe- 

 nyl mercaptan, phenyl sulphide, and diphenylcne <lisnlphide. With 

 carbonic anhydride the same i'undainental mixture yields benzoic acid, 

 with sulphur dioxide it gives benzylsulphurous acid, and so on through 

 a long list of similar reactions. In every case, however, treatment with 

 water is necessary to complete the re-action. 



In all these syntheses, according to tln^, authors, the first step appears 

 to be the formation of a i)eculiar organo-niclallic compound, as follows: 



C6Ue+Al,Clc=CfiU5.Al,Cl5+IICl. 



This compound, Cg H.v AI2 CI5, being formed, it is readily acted upon by 

 various agents, as, Cor exam[)le, by the paraffin (ddoridcs, in which case 

 hydrocarbon derivatives are produced with regeneration of aluminum 

 chloride, thus: 



C6H5.Ai,c],+cn/:i=C6H5.CH3+Ai2Ci«. 



