58 On the cultivation ofWoad Plant 



The fermentation was perfect at the expiration of 

 48 hours. The liquor being drawn off from the vats, 

 one bucket of lime water, prepared agreeably to the di- 

 rections contained in the treatise, was added to two of the 

 liquor, and then agitated with a small wooden rake for 

 fifteen minutes, when a most copious white froth arose 

 to the surface, which soon assumed a bright blue co- 

 lour ; this froth was carefully skimmed off, and put into 

 earthen bowls to dry, and gave me a quantity of u fleuree," 

 as mentioned at page 138. 



The green floculi were deposited in two hours. The 

 superincumbent yellow liquor being drawn off, an ounce 

 of sulphuric acid to every bucket of liquor diluted with 

 water, was poured into the green precipitate, which in- 

 stantly changed it to a most beautiful cerulean blue : 

 cold water was then poured into this admixture, and 

 violently agitated for ten minutes. 



Twelve hours after, the liquor was drawn off, and 

 the blue deposition put into cloth filters to drain. In 

 twenty four hours, the woad was perfectly drained taken 

 out and put into a box with a linen bottom, which was 

 placed in an airy situation under cover. At the expira- 

 tion of seventeen days, it had became a tenacious paste ; 

 it was then taken out with a wooden knife, and press- 

 ed into small boxes to dry. In two weeks the indigo was 

 perfectly dry. 



At the expiration of twenty days, the plants which 

 had been cut, were grown sufficiently large to cut again. 

 Thus seed sown in May, would give three cuttings a year 

 in this northern climate ; but if sown in September, 

 there might be four, if not five cuttings a year ; as the 



