CHEMISTRY. 447 



in the petroleum ether extract from Cascara amarga aud Phlox Caro- 

 lina, have discovered a solid, crystalline hydrocarbon, melting- at 106°. 

 In composition it is represented by theformnla CuTIia, or some multiple 

 thereof. (Berichte, xxi, 2598.) 



The synthesis of closed carbon chains. — During 1887 and 1888, W. H. 

 Perkin, jr., has published a mnnber of i)ai)ers extending his earlier 

 researches upon conipounds containing closed carbon chains. In some 

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

 gators. 



By acting upon 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 tri methylene derivatives, and also on the 

 synthesis of aromatic compounds having closed carbon chains. (See 

 Perkin, Journ. Chem. Soc, li, pp. 1, 240, 702, 849, andLiii, 1 ; Colman 

 and Perkin, ibid., li, 228, and liii, 185 ; Freer and Perkin, ibid., Li, 820, 

 and LIII, 202, 215.) The aromatic comi)ounds were also studied by 

 Kil)ping, ibid., liii, 21. None of these papers are suited for detailed 

 abstraction. 



A new (jeneral method of synthesis for aromatic componnds. — 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 anhydrides. Thus, when dry oxygen is 

 l)assed 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 up powdered sulphur, with evolution of hydro- 

 chloric and sulphydric acids, and afterwards, with water, gives phe- 

 nyl raercaptan, phenyl sulphide, and diphenylene disulphide. With 

 carbonic anhydride the same fundamental mixtnre yields benzoic acid, 

 with sulphur dioxide it gives benzylsuljjhurous 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 the authors, the first step appears 

 to be the formation of a peculiar organo-metallic compound, as follows: 



CgHe-f Al2Cl6=C6H5.Al2Cl5+HCl. 



This compound, CeHg. AI2 CI5, being formed, it is readily acted upon by- 

 various agents, as, for example, by the paraflin chlorides, in which case 

 hydrocarbon derivatives are produced with regeneration of aluminum 

 chloride, thus: 



C«Ur>.Al,,Cl5 + ClI:,(Jl=C6lIr,.CH;,4-Al2Cl,i. 



