430 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
COMMONPLACE NOTES. 
Nicotine for Horticultural Purposes. 
Lieut. G. Parry-Davis, of Borneo, gives us the following valuable 
account of a method of extracting nicotine, which may be of con- 
siderable use :• — 
" In these days, when shortage of labour hampers all branches 
of industry, it may prove of interest to Fellows of the R.H.S. and 
others to know the results of an interesting experiment I made 
with tobacco (Nicotiana Tdbacum and N. angustifolia) on my planta- 
tion in Sarawak, in the early months of 1914. 
" The labour difficulty — in this case the expense of catching 
caterpillars by hand — caused me to seek for some method of de- 
stroying them inexpensively through natural means. The rainfall, 
which in 1913 was 222 inches, is distributed, with the exception of 
some seventeen days, generally in November, throughout the entire 
year. This heavy rainfall causes ' spraying/ if done with any of 
the usual insecticides and for the usual ends, to be an incomplete and 
recurring process. 
" I therefore sprayed the area in question with the definite view 
of attracting ants (Sanba Ant, Fire Ant, or Semut Api), one of the 
caterpillars' greatest enemies. 
" With this end in view I made use of a solution of sugar-refuse, 
boiled down with a little borax and lime. This, when sprayed, 
formed a thin film on the plant when dry, and was impervious 
to rain. 
" It had an extraordinarily quick and beneficial effect. Swarms 
of large ants (Semut Api) , attracted by the sweetness of the solution, 
preyed upon the caterpillars, killing them in thousands. 
" Whether from reaction and relief from puncturing of the leaves, 
with attendant additional respiration and transpiration, or from 
absorption of the lime and sugar to build up growth, the plants 
revived magically. 
" The purpose of my raising tobacco at that period was to obtain 
tobacco with a large nicotine percentage, for use as an insecticide 
on the other crops that I was growing. 
" Realizing that the process followed by growers of tobacco 
intended for smoking (the refuse of which" is sold^ as 'Jscrap^ or 
' insecticide tobacco ') was too slow and expensive for the nicotine 
percentage contained, I determined, if possible, to produce a tobacco 
more quickly, more cheaply, and with a higher nicotine percentage. 
"I therefore tried_the experiment of bursting or rupturing the 
