Vol. III. No. .5.3. 



THE AGKICULTUEAL NEWS. 



139 



TROPICAL DISEASES AND THEIR 

 CAUSES. 



The following is an extract from the lecture on 

 ' The Disease Problem of the West Indies,' delivered 

 by Sir Patrick Manson, K.C.M.G., M.D., F.R.S., at the 

 AVest India Committee Rooms on March 8. We propose 

 to publish further extracts from this valuable lecture in 

 future issues o{ the Agricultural A^t'uv. The present 

 extract deals particularly with the causes of certain 

 tropical diseases : — 



Our knowledge of the cause of malaria and of the 

 means by which it is disseminated is even more precise. We 

 know that what we call malaria is a miiuite animal which 

 lives in the blood of man. Each blood corpuscle occupied 

 by the growing parasite is destroyed. When the corpuscles 

 so invaded break u() and liberate the little groups of young 

 parasites into which the full grown parasites divide, the 

 characteristic fever is jirodnced. Generation of parasites 

 follows generation, and in a very short time, in consequence 

 of the destruction of many blood cor{)Uscles, the patient is 

 brought to a condition of profound antemia, even if he does 

 not die of the disease. Under the most favourable circum- 

 stances he is unfitted for work for a longer or shorter time. 

 If not properly treated, his fever spells may recur during 

 .several months or years, and all this time he is more or less 

 of a burden to his friends or to the community. We know 

 now that the malaria parasite is [lassed from the sick to the 

 sound by a special kind of mosipiito, and we also know that 

 if this mosquito is [irevented from biting the sick, or if it 

 does chance to bite the sick, from subsequently biting the 

 eound, there will be no spread of the infection. 



We are not so sure about the germ cause or causes of the 

 dysenteries and diarrhcBas, but we are sure that most of these 

 diseases are caused by germs conveyed from the sick to the 

 sound, either in food or in water, or by direct contact with 

 the discharges from diseased surfaces, and, fiuther, that the 

 growth of these germs and the diseases to which they give 

 rise are sjiecially favoured by unwholesome feeding. The 

 influence of feeding in inducing these intestinal diseases is 

 specially well illustrated by what happens in most negro 

 nurseries Writing in the sixth issue of that most instructive 

 publication, the Jin'tiah (Juitiiia Medirnl Anniuil, Ur. N. 

 Barnes lemarks : ' As regards feeding, the children of our 

 populace must be ranged in two great classes. The Hindu 

 •coolies almost invariably nurse their children. With the 

 negroes it is far ditferent. Almost from the moment of birth 

 the black baby is crammed with pap made of plantain, 

 Indian corn meal, cassava starch, etc., sometimes even with 

 :S0up made of salt meat or fish. When this diet causes 

 dyspepsia, and the child, being in pain, begins to cry, the 

 usual treatment is to fill it up with more pap until it is 

 unable to cry.' Under such circumstances dysentery, or 

 diarrhcea, or convulsions, are only to be exjiected. This 

 grotesque system of infant feeding has nmch to do with the 

 enormous infantile mortality so notorious among the negro 

 races. 



DEPARTMENT NEWS. 



The Imperial Commissioner of Agriculture embark- 

 ed in H.M.8. ' Pallas ' for St. Lucia and Antigua on 

 Monday, April 18. After completing his visit to 

 Antigua it is probable that he will call at Dominica 

 and St. Lucia and return by R.M.S. 'Eden' due at 

 Barbados on the 23rd. instant. 



AGRICULTURE IN NORTHERN NIGERIA. 



In the Colonial R/'poft on Noiilwni Nigeria for 

 1902, the High Commissioner (Sir F. Lugard) makes 

 the following remarks on the agriculture of the 

 colony : — 



Additional consignments of cotton seed have been 

 received from England and distributed. Samples of indi- 

 genous cotton from each province have been sent to the 

 British Cotton Growing Association, and also some samples 

 of the cotton from the new seed, but as yet their report has 

 not been received. I hear that the latter has been valued at 

 the very high jirice of 6|(/. per fc. It is under consideration 

 to send a cotton expert to Northern Nigeria, as has been 

 done to each of the other West African Colonies, to 

 instruct the natives in the use of giiuiing and pressing 

 apparatus, and report on the suitability of various districts 

 and soils for cotton cultivation, and upon the iirospects of 

 the industry if taken seriously in hand. My own view is 

 that imported products such as cacao, improved cotton, 

 coffee, etc., should not be grown in plantations by Europeans, 

 but introduced as a crop among the agricultural \illages, and 

 their cultivation promoted liy a distribution of iilants and 

 seeds, and by a promise to Imy the produce, and hy bonuses 

 for good results in order to naturalize them in the country. 

 The extensive growth of the onion and leek throughout the 

 Hausa 8tates shows that the people readilj' adopt a new 

 culture. It is necessary to establish nurseries of such plants 

 for distribution, under the care of an expert Curator, and 

 I think it would be most useful to place in the Government 

 Gardens specimens of indigenous trees of economic value 

 (e.g., the various rublier jilants, wood-oil trees, gambia pod, 

 etc.), so that residents and others on arrival could learn to 

 recognize these, and promote their cultivation, and check 

 their destruction in their provinces. It is, above all, 

 important to teach the i>eople the use of oxen in agriculture, 

 and to introduce the American or Indian plough used by the 

 Kaffirs of South Africa. It has been pointed out bj' many 

 writer.s, that since throughout Africa oxen are only driven or 

 tended Ijy men, the introduction of ploughs has the result of 

 enianci[)ating the women to some extent from the labour of 

 field work, and causes it to be undertaken by men. ilen, 

 however, already work in the fields throughout the greater 

 part of Northern Nigeria. 



Crotons. A correspondent is anxious to obtain 

 ,a plant or two of croton ' Princess of Wales.' Possibly some 

 •of our corresi>ondents can inform him where these are 

 Available and the cost, packed ready for shipment. 



Land Crabs. Mr. Henry ;Millen, Curator of the 

 Tobago Botanic Station, writes that carljon bisulphide has 

 been found useful for exterminating land crabs which abound 

 in the Station. The following method has been found to 

 give good results : — Cotton is placed in the holes to a 

 distance of about a foot — large holes will require about a 

 handfuU. The cotton is then .saturated with the carbon 

 bisulphide, and the holes closed up. In these exi)eriments it 

 was found that a bottle of carbon bisulphide (sold locally at 

 Is. 8<f.) was sufficient to destroy from twenty-five to thirty 

 crabs. 



