GUMS, RESINS, AND OTHER VEGETABLE EXUDATIONS. 203 



Podocarpus elata, R. Br. 



Is a very common tree with us, but T have found no resin 

 upon it. 



The following references are interesting : — 

 Podocarpus ferruginea yields a dark red coloured gum resin. 

 (G. Bennett, Wanderings of a Naturalist, p. 415). 



See also "Podocarpic Acid." (Watfs Diet. viii. [2], 1657). 



Amongst the natural products collected by Dr. T. E. de Vrij, 

 during his stay in the Isle of Java, was a crystalline resin pro- 

 duced from Podocarpus cupressina or P. imbricata, a tree common 

 in the forests of Java, and known locally by its Malay name of 

 Djamoudjou. This resin, when treated with alcohol, yields a 

 white crystalline acid substance, which has been called Podocarpic 

 acid. The last number of the Journal fur praktische Chimie 

 contains a long paper by Herr A. C. Oudeman, Junr., in which 

 he describes the results of his studies of this acid, and of several 

 of its salts and derivatives. (Journ. Soc. Arts, xxii. 864). 



Note added, 24th January, 1902. 



Dr. T. A. Henry has recently published "A chemical investiga- 

 tion of the constituents of the sandarac resins," (Proc. Chem. Soc, 

 xvii., 187). He examined the North African Callitris quadrivalvis 

 and the Australian C. verrucosa. He finds the resins to be 

 identical in composition and to consist of a mixture of resin acids 

 and terpenes, separable by steam distillation. From the latter, 

 pinene has been isolated and identified. Two resin acids have 

 been isolated and examined, — one is named inactive pimaric acid, 

 and for the other the name callitrolic acid has been retained. 



The research was carried out in the laboratories of the Imperial 

 Institute, London, of which Mr. Wyndham Dunstan is Director. 



