STARCH-PRODUCING PLANTS. 329 



but, to render the action of the chemical ingredients more quick and certain, 

 it is better to discarbonise the soda before it is put into the boiler. This may 

 be done by preparing in a small separate boiler the quantity of liquid neces- 

 sary for a day's consumption, which is prepared in about an hour. The 

 carbonisation is effected in the following manner : 



Ten parts of salt of soda. J 



Six parts of quick lime. > In weight. 



Seventy parts of water (never less.) ) 



Soiling. This is a most important operation. By it the gluten and color- 

 ing matter are separated from the fibres, which separation is absolutely neces- 

 sary, in order to prepare the fibre to receive the bleaching. It is necessary to 

 observe that the three several sorts of layers which are found in the tree, and 

 which, uuder the head of " crushing," are recommended to be pressed separately, 

 should be also boiled separately, because the outermost layer has more coloring 

 matter than the next under it, which again has more than the innermost layer ; 

 As they are boiled so will they be dried and shipped, and each sort will have a 

 different price in the market ; that fibre which is lightest in color bearing the 

 preference, in consequence of its not requiring more than six hours to bleach 

 whilst the darkest will, probably from its greater tenacity, take twelve to 

 eighteen hours. It is advisable to place over each boiler the means of lifting 

 the mass of fibre when boiled, and suffering it to drain into the boiler before 

 it is carried away to be washed. This is easily effected by a chain from the 

 roof, to which may be hung a lever, having at that end over the boiler some 

 hooks attached to it, whereby the mass is lifted out of the boiler, and the 

 liquor thus preserved for the next boiling. 



Washing. It is absolutely necessary that the fibre should be well washed 

 after being taken out of the boiler, in ordsr that all extraneous matter may be 

 separated therefrom. In choosing the site for an establishment of this kind, 

 care must always be taken to make choice of a spot in the immediate neigh- 

 bourhood of a large river, or other plentiful supply of fresh clean water. The 

 machinery necessary for cleansing and washing the fibre may be of various 

 descriptions ; but, perhaps a selection from one of the three following sorts 

 will be found to answer every puipose, viz., those used by paper manufac- 

 turers in England, and by coffee planters and arrowroot growers in the West 

 Indies. 



Drying. The washed fibre, when hung over lines made of the twisted fibre, 

 or any other convenient material, will be sufficiently dry in a few hours to be 

 taken down, when more can be hung up, and then several batches can be dried 

 in a day ; and it will be necessary to have the drying ground as near the water 

 as possible, in order to save weight in carriage. 



Pressing. 'When the fibre is perfectly dry, it must be well pressed, for the 

 convenience of packing, carriage, and shipment. The hydraulic press is the 

 best machine that can be used for the purpose ; but in the absence of that, the 

 lover and screw will make a large amount of pressure available. A hydraulic 

 press of from 400 to 500 tons, will press bales of from four to five hundred 

 weight each, which will not be too large for shipment." 



STARCH-PKODUCING PLANTS INVESTIGATED. 



STAECH is one of the constituent parts in all mealy farinaceous 

 seeds, fruits, roots, and other parts of plants, and is in large 

 demand for domestic use, the arts, &c. Our common starch 

 is made from wheat, and a good deal from potatoes. Pure fecula 

 is separated by art from a variety of plants. 



Of plants yielding starch we have the Indian arrowroot, which 

 is the fecula in the rhizomata of several species of the Maran- 

 tacese. In the "West Indies it is obtained from the Maranta 



