148 SYNTHESIS OF DEPSIDES. 



fully completed owing to the fact that tannin itself has not yet 

 been synthesised. A large number of other experiments have been 

 carried out. some dealing with other commercial tannins, which 

 were purified and hydrolysed as above, others being attempts at 

 synthesis along the above lines, but these have not yielded the 

 results expected. Nor has anything occurred which has yielded 

 such strong evidence of the structure of the tannin molecule as 

 the synthesis of penta galloyl glucose. 



Other pentacylated glucoses have also been prepared, 

 namely, with para hydroxy benzoic, salicylic, and pyrogallol car- 

 boxylic acids, also probably mixtures of the a and fS stereo- 

 isomers. 



The bearing of the above syntheses on the chemical processes 

 occurring in plants is of extreme interest, as showing that the 

 polyvalent alcohols can be utilised by the plant in the esterifica- 

 tion of acids, the free acids themselves being found only in a few- 

 species, and the significance of this is of the utmost importance 

 to vegetable physiology as the sugar derivatives found so widely 

 distributed have not hitherto been regarded in this light. 



The compounds of high molecular weight and known con- 

 stitution prepared in the course of these researches are also of 

 great interest from a theoretical point of view. 



The above resume has been prepared from the various 

 papers by Fischer and his pupils published in the Bcrichtc dcr 

 Deutschen Chemischc Gcscllschaft. For other work dependence 

 has been placed upon abstracts. 



Decimalisation of Weights, Measures and 



Coinage. — The Council of the Association recently adopted 

 the following resolutions: — (i) That the metric system of 

 weights and measures be legalised at as early a date as possible^ 

 for permissive use until the end of the war, and that its use 

 become compulsory and exclusive after such time as may be 

 found practicable; (2) That the Government of the Union of 

 South Africa should co-operate with the other self-governing 

 Dominions with regard to the decimalisation of coinage; (3) 

 That copies of the foregoing resolutions be sent to (a) His Excel- 

 lency the Governor-Cieneral, (b) the Prime Minister, (c) the 

 Minister of Trade and Industries, {d) the daily Press, (>) the 

 Decimal Association, Finsbury Court, London, F.C., and that 

 they be jniblished in the Association's Journal. 



