270 , EEroKi— 181)1. 



The alpha-law in this case is expressed by saying that in the main the 

 tendency is for the beta-bromine atom to be removed. 



In the case of a dissymmetrical molecule, such as that of nitric acid, 

 the formation of the one or the other derivative will depend on the 

 nature of the addition compound — i.e., on the distribution of the radicles 

 of the acid — assuming them to be ' distributed ' when addition takes 

 place, thus : — 



NO, 



HO 



I I j + HO.NO, = 

 \/\/ 



y\/\ 



111+ HO.NO, = 



In this case the alpha-law is expressed in the statement that in the main 

 the tendency is for the acid radicle to assume an alpha-position in the 

 addition compound first formed. 



This question has already been discussed by Mr. Wynne and the 

 writer with reference to the tetra-chlorides of naphthalene and of its 

 derivatives, naphthalene tetrachloi-ide affording the three possible di- 

 chloronaphthalenes, but the 1 : 'A compound in largest and the 1 : 2 in least 

 proportion, thus : — 



HGl CI CI 



/\/^ HCl /\/\ /\/\ y\y\ CI 



HCl CI 



The behaviour of the substituted chlorides is as follows : — 



Chief product of iictioa 

 Chief chloride. of potash on chloride. 



CI Cl„ CI 



/\/\ /X/X HCl /\A CI 



I "^ M "' 



I 1 ! Ill TTpi I I I PI 



\/\y \/v/ \/\/ 



HCl M. p. = 81°. 



HCl CI 



i/\ A CI HCl /VN CI /\/\ CI 



HCl M. p. = 113°. 



S0„C1 HCl S0„C1 SO3K 



i/\A HCl /\/\ CI /V^ 



I I I Hn III I I I 



HCl CI 



