2o6 Associations and Societies 



that the nickel in the filtrate from cobalt ammonium phosphate can 

 be titrated by Cyanide without f urther manipulations ; hence the phos- 

 phate process for separating nickel and cobalt allows a separate 

 Volumetrie estimation to be made of the two metals. 



Note on a specimen of Russian oak. P. A. Ellis Richards, 

 F. I.e. The author gives the results of his examination of speci- 

 mens of oak that have been buried for many centuries in the sandy 

 bed of the river Moksha in Russia. The chemical analysis shows 

 that by the prolonged solvent action of water in the presence of a 

 soil rieh in iron, the sodium and potassium salts originally present 

 have almost entirely disappeared whilst the percentages of iron and 

 calcium Compounds have greatly increased. The oak itself still re- 

 tains its woody character although the colour has changed to a dark 

 grey or black. 



The estimation of potassium in presence of other substances. 



A. H. Bennett. The author describes a method based on a combina- 



tion of the cobaltinitrite and Perchlorate processes, which can be suc- 



cessfully used for the estimation of potassium in the presence of even 



considerable quantities of other substances, ammonium salts being 



the only substances of common occurrence capable of interfering 



with the results. The method is particularly applicable in the case 



of wine lees, argols, tartars, and in the liquors of tartaric acid 



works, where potassium occurs with free tartaric acid, sulphuric and 



phosphoric acids, iron, alumina and organic matter. Precautions to 



be observed when phosphates of iron and aluminium are constituents 



of the mixtures analysed are given, together with results obtained 



by the use of the process under varying conditions. 



Royal Dental Hospital, W. C, and 



46 Stamford Brook Road, W., London. 



II. THE BIOCHEMICAL SOCIETY, ENGLAND 



R. H. A. Flimmer, Secretary 



March 20. Botany B'd'g, Imperial Coli, of Science and Tech., 

 South Kensington, London, S. W. (5.30 P. M.)^ 



S. B. Schryver and (Miss) D. Haynes: Preparation and proper- 

 ties of plant pectins. 



2 The last preceding meeting was held on February 14. See Biochemical 

 Bulletin, 1916, v, p. 109. 



