Vol. XV. No. 383. 



THE AGRICULTUKAL NEWS. 



423 



percentage of rubber in the latex from the unmanured and 

 manured plots was 31 and 32-8 per cent., respectively. The 

 more scientific research on rubber has concerned vulcani- 

 zation, the effect of tapping on food reserves of Hevea, and 

 the resting period of rubber trees. 



The information relating to cacao in this report shows 

 that the exports and prices obtained were better than in 

 1914. Manurial experiments are being conducted with 

 cacao, also experiments to ascertain the most favourable 

 spacing for Forastero cacao at an elevation of from 500 feet 

 to 18,000 feet, at which elevation cacao is grown in ( 'eylon; 

 also the most suitable temporary shade and the best green 

 manures to apply. 



Other industries dealt with in the report are cinnamon, 

 rice, and tobacco. 



The section of the report dealing with the Royal Botanic 

 Gardens contains an extract from the report of the acting 

 Botanist and ilycologist on the Ceylon Flora. This is of 

 interest in view of the fact that there is a general impres- 

 ,sion in botanical circles in Great Britain that no attention 

 is given to pure botanical work by Agricultural Departments 

 and Botanic Gardens in the British tropics. 



Information relating to school gardens indicates that 

 the majority of school gardens continue to maintain a high 

 standard of efficiency. 



The last three pages of the report contain notes on 

 miscellaneous subjects of considerable interest. The acidity 

 of Ceylon soils has been investigated, and it is thought possi- 

 ble that the acidity of Ceylon soils has not been sufficiently 

 allowed for in manuring schemes adopted on estates, and 

 that the full benefit of ammoniacal and organic nitrogenous 

 manures, has through a deficiency of basic constituents, not 

 been attained. In regard to the shortage of potash it has 

 been shown that for tea, and to a le.ss extent for rubber, 

 potash has not the importance usually assigned to it, and it 

 is suggested that the popularity of this manure in Ceylon 

 is no doubt due as much or more to advertisement by the 

 German potash Syndicate than to the results of actual trial 

 and observation. 



There is a section in the report having reference to 

 insect pests. 



A note appears in the report pn the effect of dynamite. 

 So far as the figures go, they seem to indicate that the effect 

 of dynamite on rubber trees, manifested more in the height 

 than in the girth of trees, is not considerable. 



The report concludes with an account of the publications 

 issued by the Department, and a statement of receipts and 

 expenditure. 



LUXURY TRADE RESTRICTIONS AND 

 THE PRICE OF LIME OIL. 



A restriction in the demand for essential oils for the 

 confectionery trade, says the Fflrfuuwry ond Essmtial Oil 

 ift'corrf (November 1916), is a probable sequence to the new 

 Government proposals in regard to the national food supply. 

 These restrictions principally concern the supply of sugar, 

 and the fact that s"gar supplies have been reduced by the 

 Sugar Commission to 6-5 i)er cent, of previous supplies, 

 proves that the out-turn of confectionery must be correspond- 

 incly lessened. The above -lournal points out that the new 

 .sugar restrictions may be followed by official embargoes on 

 other luxury trades, and that the manufacturing perfumers 

 would be well advised in marshalling their influence and 

 arguments in advance 



It cannot be said, however, that a restriction in demand 

 for lime oils has yet made itself felt. In fact, the feature of 



the market for ovei- a year has been the great demand and 

 high prices paid for distilled lime oil, especially. The 

 market price for this product, which in normal times averages 

 2s. to 2.S. Qd. per lb., advanced to lO.s. per S). at the end of 

 March 1916. The price ruling during November of the 

 present year was 9s. per lb. spot, and the market was very firm 

 indeed. During this month hand-pressed oil made a big 

 advance to 1.5.<. per fii., ihe normal price for this product 

 being 6s. per ft). In the New York market during October, 

 expressed lime oil was being firmly held as supplies had 

 diminished, and the price quoted was $3-25 to SS-SS. 



It would not appear, therefore, that there is any depres- 

 sion in the lime oil trade, though it is as well to have regard 

 to the fact that restrictions placed upon other products with 

 which lime oil are u.sed in the manufactures may have the 

 result in the future of reducing the demand, and the market 

 price. 



It may be noted that during 1915-16, the output of both 

 distilled and hand-pressed oil from Dominica was below the 

 average. The shortage was largely due to the great demand 

 for raw lime juice for making beverages. Local buyers of raw 

 juice endeavoured, as far as possible, to obtain their supplies 

 from unecuelled limes so as to secure with the juice as large 

 a supply of oil as possible, the chief reason for this being that 

 lime oil is the best preservative of the raw juice. 



It is possible that the recent advance of hand-pressed is 

 the result of this reduction together with the possibility of 

 short supplies nest year on account of the damage to the 

 lime crop, occasioned by the hurricane last August. 



EFFECTS OF NICOTINE 

 INSECTICIDE. 



AS AN 



The following is the summary to a paper on this 

 subject by N. E. Mclndoo in the Joarnal of Agrivid- 

 turcd Ihsearch (Vol VII, Xo. 3). The pharmacological 

 effect of nicotine (C,,, H,, X.)on the higher animals 

 is well undetstood, but until recently there was prac- 

 tically nothing known about the pharmacological etTtects 

 of nicotine on insects: — 



(1) Nicotine spray solutions do not pass into the 

 tracha5,^nor do they penetrate the integuments of insects. 



(2) The fumes from nicotine used as a fumigant, the 

 vapours from nicotine spray solutions, and the odoriferous 

 particles from evaporated nicotine spray solutions or fr^.^m 

 powdered tobacco pass into the trachie and are widely 

 distributed to all the tissues. 



(3) Regardless of how it is applied, whenever nicotine 

 kills insects, as well as all other animals, it kills by paralysis, 

 which in insects travels along the ventral nerve cord fr'Hii 

 the abdomen to the brain. 



(4) The writer does not know just how nicotine 

 paralyzes the nervous system, but he does know that it 

 prevents the nerve cells from functioning, and that in regard 

 to the simplest animals, its presence around the cells causes 

 the same structural changes resulting in death as observed 

 when other animals of the same kind are deprived of oxygen. 

 In such cases it seems to kill physcially rather than chemically, 

 but the evidence presented does not conclusively prove this 

 view. In the higher animals it may kill by interfering with 

 oxidation in the cells. Whether this is accomplished physically 

 or chemically the writer does not know, but concluding 

 from the properties of nicotine, he is inclined to attribute 

 more to its physical effects than to its chemical effects. 



