Indigofera. diadf.lphiv decandria. ' 379 



parts of India make use of it. The process by which 1 

 obtained the colour from the leaves, was exactly similar to 

 that practised for obtaining the Indigo from the leaves of 

 JVerhnn tinctoriuni, viz. by committing them while fresh, to 

 cold water, and scalding them over a moderate fire, to about 

 one hundred and sixty degrees of Fahreidieit's thermometer, 

 the liquor m ill then have attained a beautiful deep greenish 

 yellow colour; it is then strained off clear, and while hot, 

 gently agitated in a broad, shallow, open vessel for a few, 

 (twenty to fhirly) minutes; during which time it changes its 

 colour, gradually becoming darker and darker and more tur- 

 bid when sufficiently agitated, if a little of it be viewed in a 

 clean silver spoon, or any other vessel that reflects the light, a 

 muddiness, or minute grain may be easily seen, m hich is ren- 

 dered large,and copious by the addition of a little lime-water ; 

 this foecula readily falls to the bottom, the superincumbent li- 

 quor is then poured off, and will be more or less of a clear 

 brandy colour, according as the operation has been success- 

 fully conducted ; for the more this liquor is tinged with 

 oreen, the less perfectly has the colour been separated ; and 

 the produce, of course the more deficient and less beautiful. 

 How to effect the most perfect separation, and precipitation 

 of the colour, is the grand desideratum with our Indigo ma- 

 nufacturers, and well deserves the chemist's most serious at- 

 tention. 



16. I. tinctoria. Willd. iii. 1237. 



Shrubby. Leaves pinnate ; leaflets about five paired, long- 

 obovate, smooth. Racemes shorter than the leaves. Legumes 

 reflexed, nearly straight, smooth, about ten-seeded. 



Pers. Derukht-neel, the plant ; and Neelep the Indigo. 



Arab. Izlum, or Lee-lunj the plant; and Neelep the In- 

 digo. 



Sans. Nili. 



lietfff. Nil, or Neel. 



Telini/. Neel. 



V v2 



