( 773 ) 



3 (/:-/.)= ^>\- ^fr i^) 



Tlie eqiuilioii ui" reality (2), can thus be wrillen in (he following 

 form : 



^t,~:<:r,^i\{:i-f,-:<:'r^) (lo) 



If fartherniore JS"' /, indicates a snniniation over the hiuKiinary 

 poinU, 2£"i\ over tlie ini(/<//r/(ti'j/ bDujents, then 2£t^=^'t^-{-^"t^, etc. 

 so that (10) becomes 



:^"^-^-r,=.2p-^- v',^) .... (11) 



The eqnations (2), (9) and (10) are of course but different forms 

 for the same relation of reality. 



Sneel', March 1904. 



Chemistry. — Pi-ofessor Lohky dk Bkuyn presents communication 

 N" 7 on inti'aniolecular rearrangements: C. A. Lobry de BruYxN 

 and C. H. Sli itkk. ''The ViV.CKMX'syi-rearram/cweitt ; transfor- 

 inatloii 0/' ((rctop/n'/io.r/inr into (ici'taiiil'tde dm/ its ve/ocity." 



(Commnnicatod in the nippting of Fohiiary 21, 1904). 



Among tlie many intramolecular rearrangements known in organic 

 chemistry, the one associated with the name of Beckmaxn belongs 

 to one of the most important sei'ies on account of the extent of its 

 region and its scienfitic significance. As is well known, it consists 

 in the transfoi-mation of the oximes, under the influence of a certain 

 number of reagents, into the isomeric acid amides, foi- instance : 

 R,CNOH^RC!ONHIi. Its extent is obvicuis if we rememl>er that all 

 ketones and aldehydes are capalde of yielding oximes and that a 

 large numbei- of these, j)articularly of the ketoximes, can undergo 

 the rearrangement. Its scientitic importance is chiefly due to the fact 

 that its apj)lication to the stereoisomeric ketoximes has been the means 

 of determining the coidiguration of those stereoisomers, in this manner: 



ROW RCR/ 



II -^ RCNHR/ and || -^ RHNCIR' 

 NOH () HON O 



The rean-angement generally takes place under the influence of 

 different reagents such as sulphuric acid, hydrochloric acid, phos- 

 phorus pentachloride and -oxide, acylchhu-ides, acetic acid with its 

 anhydride and HCl, zincchloi'ide, alkalis. As these substances are 

 always ap[»lied in i-elatively large quantities, it is thought most j)ro- 

 bable, that the actual rearrangement nearly always relates to inter- 



