416 MOSQUITOES OF NOETH AMERICA 



" He informed me that the presence of one of these plants in a room un- 

 doubtedly drove the mosquitoes out, and that by placing three or four of the 

 plants round his bed at night he was able to sleep unmolested without using 

 a mosquito net. This is very strong testimony to the efficacy of the plant, for 

 the house in which Capt. Larymore was living is, as I had cause to know well in 

 former years, infested with mosquitoes." 



Mr. Shipley further states that E. M. Holmes, in " Notes on the Medicinal 

 Plants of Liberia," records that when chewed or rubbed the leaves of 0. viride 

 give off a strong odor of lemon thyme, and mentions that Dr. Eoberts, of Liberia, 

 entirely substituted the use of the plant for that of quinine in cases of fever of 

 all kinds, giving it in the form of an infusion. 



Mr. Shipley's article in the Tropical Agriculturist was reprinted in the 

 British Medical Journal and was quoted in many other periodicals and in conse- 

 quence many requests for seeds of Ocimum viride were received at the Eoyal 

 Botanical Gardens at Kew from many parts of the world. About this time a 

 report was received from Dr. W. T. Prout, at Freetown, Sierra Leone, and was 

 published by Sir William Thistelton-Dyer in the London Times for July 37, 

 1903, and in Nature, July 30, 1903. Dr. Prout's report included an account of 

 experiments made with the basil plant in relation to its supposed effect upon 

 mosquitoes and he states that these appear " to dispose conclusively of the 

 plants possessing any real protective value." He showed that growing plants 

 have little or no effect in driving away mosquitoes, and are not to be relied upon 

 as a substitute for the mosquito-net. He showed further that fresh basil leaves 

 have no prejudicial effect upon mosquitoes when placed in close contact with 

 them, and further that while the fumes of burnt basil leaves have a stupefying 

 and eventually a destructive effect on mosquitoes it is necessary, in order to 

 produce this effect, to bring about a saturation of the air which renders it im- 

 possible for individuals to remain in the room. He thinks that cones made of 

 powdered basil would, when burned, have the effect of driving mosquitoes away, 

 and that the plant to that extent might be found useful. Goeldi, in Brazil, has 

 experimented with Ocimum minimum without the slightest beneficial result. 



CHINABERRY TREES. 



In spite of the statement that the chinaberry tree will protect against mos- 

 quitoes, observations have failed to show the truth of the statement, and in 

 mosquito regions people are quite as liable to be bitten while sitting under a 

 chinaberry tree as under any other tree. Nevertheless there is an observation 

 upon record which makes further experiments desirable. In the Public Health 

 Eeports, volume xxi, No. 44, Nov. 1, 1901, Dr. G. M. Corput, Assistant Surgeon 

 TJ. S. Marine Hospital Service, gave the results of experiments, conducted by 

 tempting the mosquitoes to oviposit with cans of water hung in the branches of 

 a variety of trees, to determine if any of them had a repellant effect. He found 

 that in the can hung in the chinaberry bush there were no mosquito larvae at any 

 time, although larvae were found in all of the other cans. 



