( 561 ) 



that 100 "/„ sulphuric acid contains a little SO3 and conscciueiillj 

 free H,0. 



(\ The teniperature-coefïicient for sulphuric acid a is particularly 

 lariic and increases rapidly with the tempera! 11 re ; for acid h it is 

 decidedly suialler and very small for the i)() 7„ acid. 11 will he 

 readily undersUxxl thai in (he case of the acid a liie dissociation of 

 HjSOj ink) SO., and 11, and the dislrihuliou of S( )3 between chloro- 

 form and sidphui'ic acid are modified in a lciri>,e degree when a 

 change of temperature hikes place. 



The rearrangement of atoms may noA\' l)e represented by the following 

 schemes which respectively correspond with Benedikt's formula (I) 

 and Thiele's formula (II): 



H Br 



"^'X I \oBi- -^ 



H Br 



Against the acceptance of Thiele's formule (II) it may be pointed 

 out that in the displacement a Ih- atom must first remove an tl 

 atom; this then proceeds to the () atom with migration of the double 

 bonds, a rather intricate process practically consisting of three succeeding 

 displacements. As it has been [)roved that the reaction is one of 

 the first order, two of those displacements must take place with 

 immeasura1)le velocity. Against Benedikt's formula (I) may be remarked 

 that, according to experience, the meta-position is hardh' ever selecled 

 in the migration of an atom or of groups from the side chain into 

 the nucleus. 



The hypothesis proposed by Kastle, which assumes the inter- 

 mediate formation and decomposition of non-isolated products, is not 

 at all supported by the observations communicated here. 



The investigation as to the transformation of (ribromo|>lieiiolbroiHin(> 

 will be completed and also extended to other analogous coui[)ounds. 



Geology. — "Some Nein Undin'-Cdiiihrlan Erratic-blocks from the 

 Dutch. Diluvium". By J. H. Bonnema. (Communicated by 

 Prof. J. AV. Moll). 



1. In the (ireological-iMineralogic histitute at (irojuugcMi is found 

 a })iece of sandstone which a few years ago 1 found at Odoorn, in 

 the [)rovince of Drente. With muriatic acid applied to it, there is 

 no effervescence; consc(iucntly it dcx^s nol coidain any calcium- 

 carbonate. The grains of sand are small, but with a magnifying 

 glass they may be well distinguislicd. They are |>ccnliarly lustrous. 



The colour of this erratic-block is chiclly dark-grey. In some 



' 38* 



