22 TEANSACTIOXS AXD PROCEEDINGS OF THE [Sess. lviii. 



completely destroys the stock of fish in a stream, a law has 

 been passed prohibiting its use. The root has also been 

 extensively employed by Chinese gardeners for the destruc- 

 tion of the insect pests which infest gardens and greenhouses. 

 It is interesting to note that another species, I), uliginosa, 

 Benth., is employed as a fish poison on the Zambesi, in 

 East Africa. 



An examination of the root was made by M. Greshoff in 

 1891, but a more complete investigation was made last 

 year by Mr. Leonard Wray, Curator of the Perak Govern- 

 ment Museum. He found that 2 grains of the fresh root 

 added to 1 gallon of water rapidly killed fish placed in 

 it. By exhausting the root with alcohol, acidulated with 

 hydrochloric acid, and evaporating, a gummy substance 

 separated, and was collected and pressed into a mass. This 

 proved to be the active principle, to which he gives the 

 name of " tubain." Tubain is very brittle, reddish brown, 

 quite in.soluble in water, paraflBn oil, and benzol, but soluble 

 in alcohol, ether, and chloroform. It is not an alkaloid, 

 but a resinous substance. The dried root yields 9*42 per 

 cent, of tubain by the above process, but it is hardly 

 probable that it has yet been obtained in a pure state. It 

 is intensely poisonous. Mr. Wray found that 1 part of 

 tubain in 350,000 parts of water proves quickly fatal to 

 fish, and so small a quantity as 1 part in 1,000,000 parts 

 of water killed fish in from 15 to 30 minutes. Mr. Wray 

 suggests that this substance might be employed to destroy 

 insect pests, and is well worthy the attention of makers of 

 insecticides, and of floriculturists and horticulturists gene- 

 rally. This investigation being so recent, I have thought it 

 would be of interest to the Fellows to see the specimen of 

 the root which I have shown. 



Miss ]SlADDEy exhibited a cone of Araucaria iiribricata 

 from Argyllshire. 



Professor Batlet Balfour exhibited models, by DeyroUe 

 of Paris, of a section of tree-stem and of a grain of wheat, 

 from the Museum of the Pi oval Botanic Garden ; also the 

 top of a specimen of Ahks grandis blown down in one of 

 the recent gales at Keir, and sent by Mr. Stirling-Maxwell 



