Vol. VIII Xo. ISl. 



THE AGKICULTURAL NEWS. 



lOi' 



STUDENTS' CORNER. 



pe 



Seasonal Notes. 

 April. 



1st FdKTXICIlT. 



Cane roapitig will now be in progress. Note the 

 varieties which ripen early, and those which mature' 

 late. As the canes are carted to the mill observe which 

 varieties show good powers of resistance to root fungus, 

 and rind fungus, and which kinds are badly attacked. 



Search fields of young cane for 'dead hearts.' 

 Examine them, and keep some of the caterpillars and 

 pupae of the moth borer in a box (ventilated) in order 

 to observe their inetamorphosis. 



Cotton picking is now almost over, ami in many 

 cases the fields are being cleared. What is the best way 

 to dispose of the old plants '! Discuss the merits of 

 (1) burying the plants in the soil/With the object of 

 increasing the humus in the land, and (2) burning the 

 plants. In islands where leaf-blister mite exists, 

 observe to what extent the operations of ' picking,' and 

 ■dustini'' the leaves with sulphur and lime have kept this 

 St in check. 



Discuss the question of providing shade in cacao 

 orchards. What are the points to be chiefly considered 

 in regard to this matter ^ Discuss the suliject of wind- 

 breaks, and their influence on the development and 

 yield of a cacao plantation. What is the best method 

 of treating wounds on cacao trees, which may either be 

 the result of accident, or caused by pruning :* 



Lime nurseries should now bereceiving attention. 

 Lime trees in nursery beds are likely to be suffering 

 from drought in some districts. These seedlings can be 

 creatly assisted l)y keeping up a mulch of Hne loose 

 soil on the surface. Be careful to get a clear knowledge 

 why it is that this operation prevents, to a considerable 

 extent, the evaporation of soil moisture. Consider the 

 possibility of using Bordeaux mixture, in cases where 

 there is any liability to loss from ' damping-off.' 



Questions for Candidates. 



Pkkliminakv (Ji k^tions. 



(1) What are tlie conditions neces.sary for projier 

 ^eriiiination of seeds? 



(2) How does colour atiect the .-iiparity of the soil for 

 absorbing heat ! 



(3) State the natural and artiticial manures u.seful for 

 adding nitrogen to tlie soil. How are the artiticial nitrogen- 

 ous manures obtained, and in what quantities are they 

 u-sually applied to crops grown in the West Indies ', 



InTKRMKDIATB QfESTIONS. 



(1) What is the ineaiiing of the term ' rotation of 

 crops, ' and what are the advantages connected with rotation, 

 as opposed to growing one crop continuously '. Mention 

 a rotation suitable for the district in which you live. 



(2) What is meant by 'inversion' of cane .sugar? 

 Compare the inver.sion in (I) the muscovado, (2) the 

 vacuum pan, and (3) the triple etiect processes. How may 

 the amount of inveision be minimized in the muscovado 

 process I 



(3) What action has green manure or humus upon 

 ■^a) a clay soil, and (//) a sandy soil I 



TRANSMISSION OF DISEASE BY MILK. 



Milk has long been recognized as an agent by 

 which the bacteria of certain diseases may be carried 

 from one person or anim.il to another. This is largely 

 due to the highly nutritiiJirts nature of the duid, which 

 renders it eminently suitable as a medium in which 

 bacteria may propagate with great rapidity. Hence, 

 if but a few of those organisms wdiich are the causative 

 agents of typhoid fever, diphtheria, scarlet fever, 

 tuberculosis, etc., obtain jiCcess to milk, they rapi<!ly 

 niiiltiply if the i-onditions of temperature are favourable, 

 and the liquid at once becomes a source of danger. The 

 milk is infected with the bacteria either from some per- 

 son managing the cows, or handling the milk, or they 

 may come from the body of the cows, or be introduced by 

 means of the water used in v^ashing the dairy utensils, 

 or by insects. The whole question of bacteria in milk, 

 the various kinds, and their action either in bringing 

 about changes in the milk, or in causing disease, is 

 discussed in an article appearing in the YMr-book for 

 1907 of the United States Department of Agriculture. 



As a result of the fact that certain diseases are sometimes 

 disseminated through milk, an epidemic may appear suddenly 

 and last for a comparatively short time, or the infection maj- 

 be continued tor a long period, and the development of the 

 disease be so slow and obscure that the sourc'e is unknown. 

 Cows suffer from tuberculosis of the lung.s, and a good 

 deal of evidence exists in support of the view that the tuber- 

 culosis of cattle and that of human beings are one and the 

 same disease. Although all investigators are not disposed to 

 accept this conclusion, the tendency is, among those who are 

 studying the ijuestion, to regard milk as a serious .source of 

 danger. 



A number of epidemics of scarlet fever and diphtlieria 

 have been traced to the milk supply. In such cases the milk 

 is infected either by someone suffering from the disease, or 

 by someone who has been in i;ontact with the patient. 



Typhoid fever is a disea.se that is usually considerefl to 

 be transmitted through the drinking water, which may be 

 contaminated by sewage, but occasionally it is disseminated 

 through the food. !Milk may become infected with the 

 organisms causing this disease in various ways. Contanun- 

 ated well or spring water may find its way into the milk 

 through milk jiails, can.s, or V.ottles which were not thoroughly 

 scalded after rinsing with cold water ; the cans or bottles may 

 be left to cool in contaminated water, and become inoculated 

 by the accidental addition of even a few drops of water ; the 

 cows may wade in water or mud containing the typhoid 

 bacillu.s, and the small drops of muddy water which dry on 

 the animal's tlank may carry the organisms to the milk, or 

 tlies may pass directly from the .sick room to the milk or milk 

 utensils. 



It i> well kn(]wn, too, that uncleanly, contaminated milk 

 is the cause of intestinal trouliles suffered by very young 

 children, and which help to swell the death rate of infants, 

 more especially in crowded cities. 



If milk is heated to a suitable temperature, tlie dangerous 

 bacteria are destroyed. For ordinary pui'poses, it will be 

 sufficient to heat to 1.50° F., keeping the liquid at that 

 tempeiature for twenty-five minutes. This may well be 

 effected by setting the bottle of milk in a vessel containing 

 water, and heating the water until the milk reaches about 

 l.")0" F. Tt may then be removed from the .stove, and allowed 

 to stand from twenty to iweiity-five miiuite.s, after which it 

 .should at 1 Mice be chilled, ;ui<l kejit cold until rc(|nired foru.se. 



