Dye Stuffs. 



302 



[April, 1912. 



and also interest on the capital invested 

 in the building of a factory and de- 

 preciation. With the assistance of a 

 few enterprising men in Colombo, this 

 question of the possibility of succes- 

 fully pioneering in Ceylon an indigo in- 

 dustry on up-to-date lines has been 

 brought nearer to realisation. Indigo- 

 fera arrecta and Indigofera sumatrana 

 have been experimentally cultivated 

 during the last six months in gardens 

 within Colombo city as well as at higher 

 elevations on coconut and rubber estates. 

 The plants have grown satisfactorily, 

 as could only have been expected, 

 for indigo is a weed which will flourish 

 well with ordinary cultivation in all 

 tropical and semi-tropical countries. 

 Even where it was sown broadcast on 

 totally unprepared hard laterite soil a 

 crop has been obtained, though the 

 growth is irregular. What was sown in 

 Colombo in July last has already yielded 

 two cuttings (the second cutting at the 

 rate of 14.500 lbs. per acre), and the plants 

 are shooting out well for a third cutting. 

 Plant grown in the Kalutara district 

 has been manufactured in a miniature 

 factory according to scientific methods 

 and has yielded well, the outturn of dye 

 being much greater than the Behar plant 

 yields, and was equal to 3f lbs. of 

 standard paste for 100 lbs. of green leaf. 

 You will have noted that I have added 

 to the value of the dye the estimated 

 value of the manure, which is a by- 

 product of indigo manufacture. This is 

 a most valuable asset, especially for 

 Ceylon, where the soil cries out for 

 manure more and more every year. The 

 fact that indigo cultivation and manu- 

 facture will yield as a by-product one 

 of the most valuable of natural manures 

 is one pregnant with the greatest possi- 

 bilities for this Colony. We know from 

 the experience gained in India and Java 

 that this manurial matter trebles the 

 outturn of tobacco ; that it doubles the 

 outturn of paddy, in grain as well as in 

 straw; and it will also be found very 

 suitable for coconut cultivation, for 

 cacao, and for tea* The manure, consist* 



ing of the fermented green leaves and 

 stalks, is put into heaps and kept in pits, 

 and can be further improved in value by 

 running the waste liquid after ferment- 

 ation over it. The bacterial life, set 

 going by the fermentation, helps to de- 

 compose the plant, and turns the whole 

 mass into a brown friable mould. Sir 

 George Watt, in his " Dictionary of the 

 Economic Products of India," specially 

 refers to the great value of this manure, 

 and you will find the fact mentioned 

 there that experience has shown that 

 land cultivated in indigo is greatly 

 benefited thereby. Indigo is one of the 

 few plants which enrich the soil on 

 which it is grewn (1) by the exudation 

 into the soil of nitrogenous matter from 

 peculiar root-nodules, in which through 

 bacterial action the inert nitrogen of 

 the air is worked up into assimilable 

 nitrogenous products ; (2) by the fall of 

 leaf ; and (3) by the droppings of the 

 millions of insect life which an indigo- 

 field harbours, while the long taproots of 

 the plant draw nourishment from strata 

 of soil not reached by ordinary crops. 

 This indigo refuse is called " seet," and 

 closely approximates in its general com- 

 position good English farmyard manure, 

 though it is decidedly richer in its chief 

 constituent— nitrogen. Prom 100 maunds 

 of green plant about 80 maunds, or about 

 3 tons of well-rotted " seet " are obtained. 

 Mr. Rawson, from whose report to the 

 Behar Planters' Association, pages 9—12, 

 I quote, says that, without taking into 

 consideration the very valuable manurial 

 qualities of the decomposed organic 

 matter in the "seet," its principal plant 

 food constituents per ton would be 

 equivalent to 103 lbs, sulphate of am- 

 monia, 36 lbs. sulphate of potash, and 

 13 lbs. tribasic phosphate of lime. 

 Compared with oil cake, which contains 

 only 14 per cent, of moisture, while 

 " seet" contains 70 per cent., one ton of 

 " seet " is equivalent in manurial value to 

 about 5 cwt. of castor cake. The actual 

 results are, however, even greater in the 

 case of "seet," as the plant food there is 

 in a more assimilable and subdivided 

 form than in either farmyard manure or 



