Buffer systems in Kleinia articulata

Summary The juice of the succulent stems ofKleinia articulata contains aluminium and calcium phosphate. The main features of the titration curves of the juice are reproduced in the case of young stems by solutions of malic acid containing a small amount of aluminium, in the case of old stems by solutions ot malic acid containing calcium phosphate. The amounts of phosphate and calcium increase considerably with the age of the shoots. Rough preliminary calculations from the titration curves indicate that, whereas the titratable acidity in this plant is low for a succulent, the total malate content compares favourably with corresponding data for other more acid succulents.Our best thanks are due to Mr. N. Woodhead for generous assistance in connexion with the supply of material for the work.