Browsing by Author "Worsley, R.R.Le G."
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Item The Insecticidal Properties of Some East African Plants. I.(1934) Worsley, R.R.Le G.; East African Agricultural Reseorch Station, Amani, Tanganyika TerritoryA number of East African plants, mostly indigenous, has been tested for insecticidal value as contact poisons. No new insecticide equal in toxicity to nicotine has been discovered. Two plants, Cassia didymobotrya and Barringtonia racemosa, have toxic properties slightly less than half that of nicotine used as sulphate. The plants, which grow dd, should be of value for making insecticides on those farms where they are already growing: they would not, however, be worth cultivating. No definite chemical compounds were obtained from these two plants. The toxicity of extracts of Tephrosia vogelii has been found to be of the same order as that of nicotine in the form of sulphate, and these extracts should be able to replace nicotine in all sprays against soft-bodied insects such as aphis and thrips.Item Some East African Essential Oils(1934) Worsley, R.R.Le G.; East African Agricultural Research Station, Amani, Tanganyika TerritoryThis paper contains the results of investigations by the author on essential oil-bearing plants, indigenous and cultivated, growing in or around Amani. Amani itself is situated at an altitude of 3,000 ft. In the Usambara mountains, with an average annual rainfall of about 80 in. A casual inspection shows that there are very many plants indigenous to these parts which contain more or less essential oil, and only a comparatively small number have been examined, mainly those which showed some promise of value and were not too difficult to collect. The still that has been employed for nearly all the work was made locally by the author and is of 10 gallons capacity, being designed for passing in steam for a steam distillation or for heating directly with gas at the bottom. This still was made from a 10-gallon oil drum and has been found satisfactory in every way. When only small quantities of material were available ordinary laboratory glassware was employed.
