74 



Hie Supplement to the Tropical Agriculturist 



three or four months a year. The plant will grow 

 anywhere where there is a suitable rainfall, about 

 one hundred inches a year being ideal, and will 

 thrive well up to four thousand feet. Prolific 

 yields oannot be expected, however, in the more 

 drier parts of the island. For Ceylon Arrecta is 

 undoubtedly the plant, and the other varieties 

 can be set on one. side from all consideration. 

 The Factoby Pkooess. 



The factory was, needless to say, most inter- 

 esting, for it is in this connection that the suc- 

 cess of indigo planting in Ceylon depends. Baron 

 Schrottky's process is an entirely new one, and 

 consists of four processes: 1 The Glucosode pro- 

 cess, devised to get a better and more prolonged 

 fermentation of the plant; 2. The second Steep- 

 ing process, to enable a second dye-yielding 

 steeping of the plant, which heretofore has been 

 impossible ; 3. The Alkali and acid process used 

 in the last stage of manufacture to get a separa- 

 tion of the dye in the beating vat; and 4. The 

 Fecula process to manipulate the indigo fecula, 

 so as to convert it into a marketable standard 

 paste of keeping qualities. 



Apparently it is in the factory stage and in 

 the cheapening success of this stage that the re- 

 suscitation of the industry depends. Synthetic 

 dyes have usurped the position of natural 

 indigo largely by their cheapness and facility 

 of use. Scientific cultivation and manufacture 

 is, therefore, essential to revivify the 

 natural product which is far superior to the 

 chemical product for its colour, its lasting 

 qualities and its lack of injury to the fabric. 

 To be successful, natural mdigo, therefore, has 

 to be cheap in order to compare favourably with 

 the manufactured product, and in suitable form 

 to compete with the synthetic dyesiu ease of use. 

 The old natural indigo was sold in the form of a 

 dry dye, and expensive crushing apparatus had 

 to be installed to reduce it to a usable fluid. 

 The old type also had a great disadvantage in 

 its lack of consistency of colour. There was a 

 problem that would have to be solved to enable 

 natural indigo to compete with synthetic on 

 more equal terms. Manufacturers wanted the 

 natural product after a few years' use of the 

 chemical composition, which soon lost its colour, 

 injured the article, and generally could not be 

 compared with the old method. Competitive 

 prices and its cumbrous methods militated 

 against it. Without exaggeration Baron 

 Schrottky appears to have solved the problem. 

 The New Method. 

 The factory is a simple structure. On the 

 highest terrace are six teeping-tanks. On the 



next three beating vats, and below them the 

 straining tanks, the water and chemical-tanks. 

 On the lowest terrace are the two presses whioh 

 bring the paste to its marketable form. The 

 plant cuttings are brought to the steeping-tanks 

 and laid down and covered with bamboo poles 

 to keep out the air. Iron girders are used to 

 control the pressure. Water is supplied to the 

 cuttings by means of perforated tanks which 

 supply an even flow and prevent the entry of 

 air. For some hours the plants are then left to 

 soak and ferment. Under the old process a second 

 steeping of the plant was impossible as no 

 method could be found for preventing air get- 

 ting to the fermented plant. Baron Schrottky's 

 scheme provides for a second steeping by an in- 

 genious process. At the bottom of the tank is 

 a psrf orated pipe which allows the fluid to be 

 taken off gradually and evenly. By means of 

 the perforated tanks, referred to above, fresh 

 water can be put in without deleterious air 

 reaching the plants. By means of the drainiug 

 pipe, the fluid, which is of a golden colour, is 

 taken off into the beating tank where it is 

 treated by a kind of revolving fan and the con- 

 stituents thoroughly separated. The superfluous 

 water is then drawn off and the fecula left at 

 the bottom. Meanwhile the second fermenta- 

 tion is at work. The fecula is then drawn off by 

 means of pumps into the straining tanks where 

 it lies until it becomes of the consistency of 

 butter. Afterwards it is placed in numerous 

 cloths and thoroughly pressed until it forms a 

 paste which is subsequently packed in lead 

 lined boxes and marketed, 

 A Test. 



This,briefly, is the process. At the time of our 

 representative's visit one of the tanks was being 

 cleared of the plant which had been steeped 

 twice, (and of this residue more later,) and a 

 quantity of golden-coloured liquid was still in 

 the tank, this being the third time that water 

 had been put in it. Baron Schrottky remarked 

 that there was still plenty of dye in even this 

 third soaking, and a bucketful was secured for 

 testing purposes. Some of the chemical liquid 

 was poured into the bucket and the fluid vig- 

 orously stirred. The yellow colour gradually 

 gave way to a dark blue, and indigo froth 

 appeared, which, according to the Baron, is a sure 

 sign of the presence of dye. A small quantity 

 was poured into a saucer and revolved slowly. 

 The Indigo fecula could then be plainly seen 

 floating in the slight film of water at the bottom. 

 A Big Ceylon Average. 



One of the presses was opened and the indigo 

 paste exposed. It was of fine deep colour and 



