282 



TROPICAL AGRICULTURE 



CHAP. 



Washing the 

 starch. 



Draining 

 and drying 



The advan- 

 tages of 

 quick 

 drying. 



The air to be 

 excluded 

 from the 

 arrowroot. 



and the water can be drawn off. The fecula is then stirred 

 up with fresh water, passed through a second sieve of a 

 finer mesh — which may be of brass wire or musHn, and 

 allowed to settle as before, the supernatant fluid being drawn 

 off when all the starch has fallen to the bottom. This 

 process may be repeated several times, or until the water 

 appears perfectly clear over the starch. The object of the 

 several washings is to remove everything from the pulp but 

 the starch, which, in its pure state, is the arrowroot of com- 

 merce. After the last washing the water is drawn off, and 

 the pasty starch is taken out of the tubs or vats and put on 

 trays with calico bottoms to drain and to dry, the drying 

 process being usually effected in the sun or in sheds, the 

 sides of which are left open or enclosed simply with gal- 

 vanised wire netting to allow a free circulation of air. In 

 Bermuda it is calculated, according to Simmonds, that 

 " four barrels of peeled and cleaned rhizomes will yield in 

 ''good seasons about loo lbs. of good arrowroot, and will 

 "take from five to six puncheons of clear soft or tank water, 

 " it will be about twenty-fours hours in the water from the 

 " time of grinding till it is upon the cloths or drainers." The 

 arrowroot will take about three or four days to dry properly ; 

 but the hotter the sun or the drier the air and the more 

 quickly the product is desiccated, the whiter will be its colour 

 and the better its quality. After it is dried the starch will 

 be in cakes which will have to be broken up into small lumps 

 before it is packed. Arrowroot, when made properly, will 

 keep a very long time without spoiling if it be packed so as 

 to exclude the air, for it absorbs moisture readily, and it 

 acquires the odour of any decomposing or strong smelling 

 substances brought close to it. Unless, therefore, it is sealed 

 up in tins, it should not be shipped in vessels carrying sugar, 

 hides, &c. In St. Vincent, the arrowroot is shipped in tins 

 containing 25 lbs. or 50 lbs., and in well-coopered American 

 flour barrels, which are lined with paper gummed together 

 with arrowroot paste. 



