191 



Some difficulty, however, is met with in the germination of the 

 seed, due to the hard testa or outer-coat. In Behar specially con- 

 structed machines have been used for scratching the seeds to admit 

 of the penetration of moisture. This treatment has been considered 

 satisfactory, but somewhat difficult of application, owing to the fine 

 adjustment of the machine required to produce good results. 



Another method consists in treating the seed with strong sulphuric 

 acid. The process is as follows : — a The seed to be treated is placed 

 in a large water-tight wooden vessel, and undiluted commercial 

 sulphuric acid is poured over it and it is stirred with a wooden or 

 iron instrument until every seed is wet ; it is then left for the action 

 to proceed for exactly half an hour. At the end of this time, a large 

 quantity of clean cold water is rapidly poured on to the seed, which 

 is thoroughly stirred meanwhile. The seed is then allowed to settle 

 to the bottom of the vessel and the water poured off. A fresh supply 

 of clean water is then added, and the seed thoroughly washed and 

 the water poured off as before. This is repeated a third time, after 

 which the seed should be free from acid. It is then spread out in 

 the sun to dry and is ready for sowing. The proportions of substances 

 used for the treatment, which should be strictly adhered to are : — 

 Seed, \ maund (about 41 lbs.) ; Acid, 5 seers (10i lbs.) ; Water, 20 gallons 

 for each washing. It is not recommended to treat more than half a 

 maund of seed at a time. The method has the advantages that all bad, 

 hollow seed and other impurities float up, and may be poured off 

 during the washing operations, and the appearance of the seed is 

 very considerably improved. It is not advisable to keep treated seed 

 through the rains, unless it is put into sealed tins, as it is liable to 

 deteriorate " (Agric. Journ. India, i. July, 1906, p. 262). 



Ref. — " On Testing Indigo ; with notes on a yellow compound 

 found in Java Indigo, Rawson" reprint from Journ. Soc. Chem. 

 Industry, 31st March, 1899, pp. 1-8 (Eyre & Spottiswoode, London, 



1899). " On the occurrence of Hard Seed in Indigo f era ar recta" 



Leake in Journ. Roy. Hort. Soc. xxix. 1904-05, pp. 65-67. " The 



Germination of Java Indigo Seed," Agric. Journ. India, i. July, 



1906, pp. 262-263. " Indigo Seed Selection," I.e. ii. July, 1907, 



pp. 296-297. "Indigofera arrecta," in Comm. Prod. India, Watt, 



p. 661. 



Indigofera diphylla, Vent.-, Fl. Trop. Afr. II. p. 74. 

 III. — Ventenat, Choix PI. Jardin de Cels, Paris, t. 30. 

 Katagum (Dalziel No. 30, 1907, Herb. Kew). 



Used as a dye by the natives in Senegambia (Moloney, For. W. A IV 

 p. 311). 



Indigofera endecaphylla, Jacq.\ Fl. Trop. Afr. II. p. 96. 



III.— Jacq. Ic. iii. t. 570 ; Pal. de Beauv. Fl. Ow. Benin, ii. t. 84 ; 

 Bot. Reg. (1824), t. 789. 



Eleven-leaved Guinea Indigo (Bot. Reg. I.e.). 



Lagos : Ebute Metta (Millen, No. 19, Herb. Kew) ; found also in 

 Senegambia, Gold Coast, Dahomey, St. Thomas, Angola, Zambesi, 

 Natal and the Cape. 



Believed to be the plant used by the natives of Oware and Benin 

 to colour the calico for their principal garment— pagne or cotton 

 drawers (Bot. Reg. I.e.; Moloney, For. W. Afr. p. 1)10, from Palieot 

 de Beauv. I.e. p. 44). 



Indigofera hirsuta, Linn. ; Fl. Trop. Afr. II. p. 88. 



