No. 129. 1 443 



It has been shown that indigo is composed of the salt and sub- 

 stance of the leaves, and rind of a plant of the same name ; so 

 that we may, with propriety, say that it is a dissolution of the 

 plant, caused by the fermentation it has excited in the water it 

 was laid to steep in. 



This plant requires a good, rich, well pulverized alluvial soil, 

 which it impoverishes exceedingly. The seeds may be sown one 

 foot apart in the row, and the drills placed two feet apart, and 

 kept clean by means of a cultivator. Quantities of indigo have 

 been sent abroad from the south ; but in consequence of pouring 

 lime water into the fosces of the plant to make it subside, they 

 injured the indigo to such an extent, that it was found difficult 

 to dissolve it. They likewise sowed their seed too thick, which 

 eaused the plant to grow spindling, and devoid of succulent 

 green leaves. They permitted the plant to stand too long before 

 it was cut, consequently, but a small portion was dissolved by 

 fermentation, and that not half as beautiful as the fosces of the 

 young and luxuriant plant. It should be cut just before the 

 flowers come out into blossom, to make indigo worth $1.40 per 

 pound ; that cut at a later period will make an inferior article, 

 worth about thirty cents. It should not on any account, be cut 

 immediately after rain, but during dry weather. 



Frequently it is steeped too long : a practical indigo manu- 

 facturer can discern by the smell of the liquor, when it is in the 

 proper state to draw ofif; sometimes it is ready in six or seven 

 hours, at other times from twenty to twenty-four hours will be 

 required, owing probably to variation in the atmosphere. This 

 is the point necessary for the operator to attend to, and if he 

 does not understand it, his loss will be inevitable. Another point 

 requiring particular attention is the beating process, which is 

 seldom in this country continued sufficiently long to precipitate 

 all the green particles ; that portion remaining is soluble when 

 coming in contact with water, and is consequently lost. The 

 best indigo ever made in the United States was manufactured by 

 Gen. Hampton, of S. Carolina — with him we lost the secret. 



Prussian blue is a splendid intensely dark-blue pigment, which 

 was discovered in 1710, by i Prussian chemist, accidentally. It i? 



