I 
INTRODUCTION 
9 
one most regularly used by the Chinese, in the Malay 
Peninsula, for treating their vegetable and other 
crops. 
The plant known as tuba [Derris elliptica) is a 
woody climber propagated by cuttings. It will grow 
in any corner of the garden and soon develops into a 
fairly large mass of stems, lying on the ground. The 
roots are pounded up in water and the decoction poured 
or sprayed over the crop, where it will kill all cater- 
pillars, grasshoppers, and other insects. It is perfectly 
harmless to any plants. The decoction is poisonous to 
human beings, but only when taken in large quantities, 
and risk from it in the case of any of our spice plants 
is infinitesimal. 
FUNGICIDES 
The best of all these is the preparation known as 
Bordeaux mixture. This consists of a mixture of copper 
sulphate and lime in water. The best formula is : — 
Copper sulphate (bluestone) . . 4 lb. 
Quicklime (in lumps) . . . 4 lb. 
Water ...... 50 gallons. 
No estate should be unprovided with a bag or two 
of copper sulphate in case of an outbreak of any kind 
of fungus. I have arrested many outbreaks of different 
kinds of fungi on roots, stems, and leaves of plants by 
the use of this excellent mixture. 
It is sometimes complained that under certain 
circumstances it burns the leaves of young plants. I 
have never seen this occur. 
A very complete account of the making and use of 
Bordeaux mixture was published by Mr. E. S. Salmon 
in the Journal of the Board of Agriculture, vol. xvi. 
No. 10. I reprint the following extracts from his 
article : — 
In purchasing copper sulphate, an article of 98 per cent 
purity should be demanded; substance described as “ agricultural 
