On Indigo. 439 
Some of the samples 1 have tried and the 
results are as under: 
1.—Precipitated and sublimed Indigo, each 1 grain, 
gave nearly the same results. Each of these required 
140 grains of the oxymuriate of lime solution, correspond- 
ing to .25 parts of a grain of oxygen. The yellow liquid 
obtained was 3600 grains. 
2.—Flora Indigo, 1 grain, required 70 of the oxymuri- 
ate, = .125 parts of a grain of oxygen, or one half of 
the other. 
The same result froma sample marked J. R. best. 
3.—Indigoes marked I P and 3 P required about 60 of 
the oxymuriate. 
4.—Those marked J. R. middle, J. R. worst, and 4 P, 
required about 50 oxymuriate. 
5.—That marked Wood was rather inferior to the above, 
bat required above 40 oxymuriate. 
6.—Those marked 2 P and 1194, were the lowest I 
have examined; 1 grain of each did not require more than 
30 oxymuriate, or 35 at the most. A poor turbid yellow 
liquor was produced. The sample 2 P, when burned, 
yielded about 30 per cent. of fine sand. 
Upon a review of these experiments, Iam 
persuaded that to destroy indigo by oxymu- 
riatic acid, twice the quantity of oxygen is 
necessary that is required to revive it from 
the lime solution. 
