3i3 
Some of the older trees have been experimentally tapped, but 
1 am told that the results of tapping are not satisfactory , and the 
wounds heal very slowly. 
More is hoped for from the process of extracting’gutta} from the 
leaves. 
Only Dichopsis oblonglfolium is planted, 
R. N. BLAND. 
THE MOSQUITO PLANT. 
Report on the Basil Plant ( Ocimum viride) in relation to its 
effect on mosquitoes. 
1 his investigation, the results of which are given below, origina- 
ted in a number of statements which were made in the medical and 
lay Press, to the effect that the basil plant ( Ocimum viride) pos- 
sesses the property of driving away mosquitoes, and that, to quote 
the words which appeared in the British Medical Journal. (31st 
January): — “Captain Larrymore found that the presence of 
one of these plants undoubtedly drove the mosquitoes out, and that 
by placing three or four round his bed at night he was able to sleep 
unmolested without using a mosquito net. ” (The italics are mine), 
it was further claimed by Captain Larrymore, in a letter to the 
Times, that a mosquito placed in contact with a basil leaf died in 
a few seconds. While, on the one hand, a plant which could be 
shown to possess these properties, would be a most invaluable 
addition to our means of protection in malarious countries, on the 
other, if it did not possess them, the publication of such statements 
would be apt to do an immense amount of harm by producing a 
false feeling of security and by inducing people to do away with 
the complete protection of the mosquito-net, in favour of the im- 
perfect protection of a few basil plants placed around the bed. His 
Excellency the Governor therefore requested me to experiment with 
the view of ascertaining whether the basil plant possessed these 
properties. And first as to the results of enquiries among the natives 
of Freetown. 1 was unable to ascertain that a knowledge of this 
property was universal, though a few people were to be found who 
said that they had heard that it would drive away mosquitoes. It 
certainly is not used to any extent for this purpose in Freetown. 
Dr. Romer who was aware of this belief, informs me that he had 
tried it several times, hung round his bed. His impression was that 
while it appeared to drive mosquitoes away at first after a little 
they came back and he was bitten during the night. Others who 
have made the same experiment have also concluded that it does 
not offer a permanent protection during the night. 
It is evident however that x'ough experiments of this kind are 
open to several objections and have very little scientific value, es- 
pecially as the personal equation enters largely into them. First 
of all^ the individual may not be susceptible to mosquito bites, and 
