Vol. XVII. No. 420. 



THE AGRICULTURAL NKWb. 



175 



Reference is made to a troii blesoiue pest known as 

 "the marabu {Dichi-nstachys nutans), a leguminous shrub 

 closely resembling the acacias. It is indigenous to Senegal 

 ■•but has become firmly established in Cuba. It takes pos- 

 session of land, forms a dense spiny impenetrable growth, 

 and in some cases has compelled the diversion of roads and 

 the removal of houses. 



Numerous remedial measures, stimulated by the offer 

 -of a reward, have been suggested and tried, includini; 

 cutting, burning, poisoning, the use of bacteria, fungi, 

 insects, and twining plants, none of which appears so far to 

 be regarded as affording an adequate remedy. 



W.N. 



BAUXITE IN BRITISH GUIANA. 



The geological and analytical examination of the soils 

 ^nd rocks of British Guiana, carried out during some years 

 past by Professor Harrison, C.M.G , Director of Science and 

 Ajiriculture of the colony, has led to the discovery of 

 numerous and extensive deposits of bauxite. Some of these 

 -deposits have been leased for working to an American 

 company, but the lands already leased by no means exhaust 

 the deposits of the mineral in the colony. 



The importance of conserving and developing the bauxite 

 •deposits of British Guiana is due to the prominent place 

 that aluminium holds in modern industries, and bauxite is 

 the necessary raw material required for the producticm of this 

 metal. This importance, it seems, will become greater than 

 «ver, because aluminium has become an essential for the 

 motor and aircraft industries. 



The manufacture of aluminium from bauxite consists 

 of two stages: (a) the production of alumina from bauxite, 

 which is done by refining bauxite; and (b) the transformation 

 of refined alumina into aluminium by electrolysis, using 

 cryolite as the electrolytic flux. 



By feeding alumina into cryolite in electric furnaces of 

 special construction, decomposition takes places, and metallic 

 aluminium is tapped at intervals from the bottom of the 

 furnace. Besides the production of aluminium, fresh uses 

 -are constantly being found for bauxite, which seems to have 

 an ever-increasingly wide possibility of application. 



Up to the present, Great Britain has been chiefly 

 dependent on France for the supply of bauxite. It is 

 therefore most advisable that all souices of supply within 

 the Empire should be developed and controlled for our own 

 use, so that the British Empire should no longer be depen- 

 dent on foreign countries for the supply of the raw material. 

 In the manufacture of aluminium the three principal require- 

 ments are: (1) cheap electrical energy; (2} bauxite; (3) cryolite. 

 It is true that cryolite in its natural state is only obtain- 

 able from Greenland, but on the other hand, this 

 mineral is produced synthetically. With the large deposits 

 of bauxite, and possessing in the Kaieteur Falls a source of 

 electric power greater than that of Niagara, British Guiana 

 \i most favourably situated to enable it to become a most 

 important producer of aluminium, and it would be a very 

 short-sighted policy if the deposits of this mineral were to 

 be alienated from the control of the Government, or not 

 utilized for the benefit of the Empire at large. 



Sir Francis Watts, the Imperial Commissioner of 

 Agriculture for the West Indies, has for some time believed 

 that there were deposits of this mineral in some of the 

 smaller West Indian islands. Early in this year he forward- 

 ed a box of simples of minerals to Professor Harrison for 

 examination. In his report Professor Harrison states that 



a sample from the small island of Balliceaux, near St. Vincent, 

 consists of a hydrated aluminium silic.tte w'th alunite- He» 

 says that the finding oi tne potash and aluminium containing: 

 mineral, alunite, the presence of whu.'h is indicated by thfe. 

 analysis of the specmiru, is of some interest now when, 

 available sources of soluble potash salts are of great impor- 

 tance to the Empire. 



He advises that a search should be made in Balliceaux; 

 for more promising deposits of alunite. 



AGRICULTURE IN GRENADA. 



A copy of the progress report on the work of the Agri- 

 cultural Department, Grenada, for the quarter ended March 

 31, has been forwarded to this Office by Mr. J. C. Moore^ 

 the Superintendent of Agriculture. 



A scheme to facilitate the Agricultural Dep*rtment's 

 activities in prosecuting a vigorous campaign against cacao 

 thrips was submitted to the Board of \gnculture, and, with. 

 some amplification in special coiumitite, was adopted. 

 A scheme for the erection ol a corn drii-r and gianary vo. 

 Grenada has also been prepared and submitted for the 

 approval of the Goveriimen'. 



Details of work in ihe Botanic Gardfus include result* 

 of experiments with onions Sown in November and trans- 

 planted in December theSf are repori ed to have done fairly 

 well. It is observed, however, that had tht re been universal 

 showery weather during i^'ebruary and M.trch. there undoubt- 

 edly would have been a failure as the result of such unavoid- 

 able late sowing. Trials m a few private aardens have- 

 also given very promising results. I. is estimattd that; 

 about 20 acres, yielding at the rale of 8,000 ft), per acre, 

 would provide Grenada with onions eqiiallinB the quan- 

 tity imported during 1916 If such a yield can be 

 obtained, there is the po.ssibility of estaolishing another 

 minor industry capable of yielding the growers a good profit, 

 with onions retailing at 'id. per » . With skilled and indus- 

 trious work, onions from Teneriffe seed should with hired 

 labour, be produced at a cost of one to one-and-a-half cent, 

 per Dt). The Department is trying to arouse interest in this; 

 new industry, to which end an order for 25 lb of seed from 

 Teneriffe has been placed with the Imperial Commissioner 

 of Agriculture. 



Spraying appliances and materials have been imported 

 by the Agricultural Department in readiness for a vigorous 

 campiigu against the cacao thrips. Six estates now have 

 suitable spraying outfits, and four others have them on order. 

 In this connexion it may be mentioned that the presence of 

 the black weevil of banana {^Sp he nop horns sordidus) has been 

 recorded in coconut plots, and steps are being taken to 

 ascertain its distribution. 



Plant and seed distribution for the quarter totalled — • 

 plants, 4,6-58; seeds, 1,700. In addition, 2,000 seed coco- 

 nuts were imported for planters. The Department obtained 

 8 tons of yam plants for distrib'ition in May. Ground 

 provisions are stiil fairly plentiful, with moderately high 

 prices ruling. 



Accompanying the foregoing are monthly reports of the 

 Agricultural Instructors for March last. Perusal of these 

 shows steady progrt-ss in agricultural pursuits among the 

 peasants, and it is interesting to note that the Depart- 

 ments activities in connexion with the local food crops 

 campaign have been productive of better organization as 

 compared with last year's efforts, and the work is proceeding, 

 satisfactorily. 



