( 663 ) 



In the same way the formula (3) gives 



^, = è («0^ 4- «1^) + k («1^8 — ^i«s + «A — ^3«6 + «5^ — V7 + • ) 



^t = \ («0^3 + «1^3) + 2 («1*4 — ^5 + «3^.— ^4«7 + «6^8 — ^fl«9 4- . ) 



<^4 = 2 M4 + «1^8 + «8^1) 4- k («1^6— ^i«5 + o,b^ — b,aj 4- aj), — h,a, + . .) 

 ^6 = i («0^5 + «1^4 4- «8^) 4- h («1.^6- ^3«7 + «sVM» + «6^o-^«aii 4- • •) 



4- h («1^7— ^«7 4- «8^» — V» + «6^u— ^.«n 4- • •) 



from which the following relations may be obtained 

 111 jr»- 1 



1».3» 3'. 5» 5^7' 16 2 



1 _ 1 1 1 _ jr' 31 



43» ~ 2^ ^ 6^~ 47^ ^ 12 ~ 54 



1 1 1 1 _:r» 4 



5T'~E5^"^7^""3T*'^ le^g 



J^ 1^ 1 1 _7r' 187 



tTp r7'^9!3^~3^»"^' 24~675 



Chemistry. — ''On a crystallised d. fructose tetr acetate" , by Dr. 

 D. H. Brauns. (Communicated by Prof. A. P. N. Franchimont). 



. Very few crystallised derivatives of d. fructose have as yet been 

 obtained. A pentacetate was described by Erwigs and Koenigs as a 

 gummy substance. A number of researches have shown, however, 

 that the high temperature at which the reactions generally took place 

 causes a conversion or decomposition of the fructose. As no satis- 

 factory results were obtained with acetic anhydride and acetyl chloride 

 acetyl bromide was employed which reacts at a comparatively low 

 temperature. The greatest possible precautions were taken to exclude 

 moisture and to let the reaction take place at a low temperature. 

 The details will be published in full later on. 



Refrigerated d. fructose in fine powder was mixed with a little 

 more than 5 mols. of acetyl bromide at — 15° and after starting the 

 reaction by touching one spot with a tube having the ordinary 



