Vol. VIII. No. 18.3. 



THE AGRICULTUKAL NEWS. 



135 



COPRA. 



There appeals h> be great variatiou in the quality of 

 copra placed on the market, des|iite thcl fact that a good 

 ()iiality product is always in .satisfacti>i-v demand. The copra 

 produced in Ceylon and in the islands opj the Pacitic, where 

 large European soap-making and other fij^ns have extensive 

 interests, is always of high quality, and ^qmniands the best 

 price. Copra from the Malay States, l©wever, sells at a 

 secondary price, and is reportedto liave.._fgg(^uently been pre- 

 pared in an unsatisfactory manner. Wtele the best copra 

 at Singapore sells for about $7'50 per picul (133-i tb.), the 

 market jirice of lower qualities is often SI '00 per picul below 

 this. These lower grades are usually prepared on estates 

 owned and managed by Malays and Chinese. Although 

 West Indian copra does not fetch the high returns of two 

 years ago, it is satisfactory to note that ' prices have lately 

 .shown signs of advance, and the latest iiuotation is about 

 £19 per "ton. 



THE ORIGIN AND DEVELOPMENT OF 

 THE FLORAL CUSHION IN CACAO. 



In a pamjihlet on the ' Witch Hrooni ' disease of 

 Cacao, Dr. C. J. J. van Hall and A. W. Drost liavc 

 given a full account of the origin of the cushion in 

 cacao. For this purpose the}' studied the development 

 of the lateral buds in Thaihrouin, hicqior, a, tree nearly 

 allied to the cacao. i"- 



The buds are liorne on fairly young branches {A in the 

 accompanying diagram) in the angle between the leaf and the 



Fig. 17. Cai ao 1!ram h w ri'n Fi.owkrs. 



Iiranch. In the dowering season the bud grows out in 

 a central shoot a, and is terminated by, a flower boine on 

 a short Jlower-stallc <■ ; from the sides of the central shoot 

 secondary branches /j arise, each of ^vhi(jh is terminated by 

 a Hower also borne on a shoit stalk, it." 'f" 



In this way ten or twelve Howers iiv.if he borne on a floral 

 branch. The flowers eventually gi\e rise_^ to fruit. 



In TIieohi-Dina cacao, the cacao proper, practically the 

 same thing occurs, with this difference ; that in tliis case the 

 flowers and fruit arise only on tliose parts of the tree that 

 liave lost their leaves and become woodjt, such as the main 

 trunk and older branches. I, 



Ihe bud from which the flowers aviso Vvas originally 

 home, as in Thcoliromn /licolm; in the a.\il of a leaf, but it 

 remained dormant until the leaves had all fallen and the 

 J>ark had grown nji round it. 



After the (lowers liave fallen, the central axis of the 



original bud thickens n\> and becones the cushion. Duly 

 a few of the flowers form fruit, so that usually each cushion 

 l)ears only three or four fruits. The fruit when ripe falls off, 

 leaving the central axis or cushiart to again bear flowers and 

 fruit in the following years. 'ij 



To summarize, the cushion ^i the remains of the central 

 axis of a bud, originally borne in/t.he angle between a leaf 

 and a young branch, but ^\•llic•h ^oes not develop until the 

 branch on w-hich it-is borne Im j|,st its leaves and becomes 

 hard and woody. t' 



SUPERPHOSPHATE. 



Superphosphate, as is generally known, is made by 

 the action of sulphuric acid on mineral phosphates, 

 steamed bone, or bone ash. Raw bone is seldom used 

 for the purpose, since the organic matter interferes 

 with the action of the aciil and the after-usefulness of 

 the manure. 



Mineral phosphates, as co]irolites, are by far the chief 

 source of superphosphate. In these minerals the phosphoric 

 acid is present in the form of tribasic phosphate of lime, being 

 combined with the maximum quantity of lime required for its 

 complete neutralization (three proportions of lime to one of 

 iihosphoric acid). In this state it is insoluble in water. The 

 sulphuric acid is added in quantity sufficient to combine with 

 two propiirtions of the lime contained in the mineral, gypsum 

 or calcium sulphate being formed as a result. Monocalcic 

 phosphate is also formed, andjin this, one proportion of 

 phosphoric acid is combined with one proportion of lime, the 

 comjiound being .soluble in water; It will be seen, therefore, 

 that superphosiihate consists chiefly of a mixture of calcium 

 sulphate and soluble monocalcic jihosphate. In addition, 

 there is always some tribasic iJjosphate pre.sent which has 

 not been rendered soluble : this is usually from 4 to 6 per 

 cent, in amount. J 



The price of superphosphatfe is naturally based on the 

 I)roportion of soluble i)hosphate it contains. This is usually 

 expressed in the guarantee accompanying the manure as the 

 amount of tribasic phosphate made soluble. When a super- 

 phosphate is de.scribed as a 30-per cent, super., it means that 

 a contained weight of tribasic phosphate, equal to 30 per 

 cent, of the whole mixture, has been rendered soluble. As 

 a matter of fact, however, the actual quantity of monocalcic 

 ]ih(>spliate, or superphosphate of lime, is considerably less — ■ 

 ■22(> per cent. 



In fixing the price of the manure, the insoluble 

 ]ihosphate and gypsum are not taken into consideration. 

 They have, however, a slight manurial value. It should be 

 pointed out, too, that the phosphoric acid in the 35-per 

 cent, superphosjihate is not worth' any more per unit than 

 that in the 2G-per cent, manure, but in making the former 

 more expensive material of higher quality is required. 

 When carriage has to be paid on the manure over a long 

 distance, the higher grade superphosphate will often prove the 

 more economical, since a greater quantity of phosphate is 

 obtained for each ton of carriage paid. 



It may be added that in addition to the monocalcic 

 phosphate, insoluble phosphate, and gypsum, a superphos- 

 phate also contains proportions of sandy matter, water, and 

 small quantities of oxide of iron and alumina. Those mineral 

 phosphates which contain the smallest quantities of iron and 

 alumina are the most desirable ,for making superphosphate. 

 The monocalcic [ihosphate has an affinity for these 

 cmnpounds, and will recombin(j,,.with them, thus giving rise 

 to what is known as reverted pliospliatc, which is insoluble. 



