PLANT ANALYSIS AS AN APPLIED SCIENCE 205 
solubility of indigo in sulphuric acid is utilized for blue dyeing 
of wools. 
Indigo has been made artificially by several methods, though 
the process so far is too expensive to allow the manufactured 
compound to replace the commercial supply from plants. 
The table of statistics is as follows: — 
Amount of indigo 1 imported: 
Pounds. 
Value. 
1884.. 
$2,267,048.00 
1885. 
. 3 , 035,934 
2,007,066.00 
Artificial indigo: 
Pounds. 
Value. 
1884... 
None. 
1885. 
. 3 , 3 oo 
$3,600.00 
The dye commonly known as logwood has been cultivated 
in Jamaica 2 since 1715, and has been known and used in 
Europe from a short period after the discovery of America. 
The commercial supply of the dye is from Hematoxylin 
campechianum , a tree belonging to the natural order Legumi- 
nose. It is the wood of the tree which is used, and is met in 
commerce in the shape of large, irregular blocks. 
The only other tree besides logwood in which hsematoxylin 
so far has been discovered is the Saraca indica, of the same 
natural order. 
I stated 3 before the Academy of Natural Sciences, in Nov¬ 
ember, the discovery of this principle in my analysis of the 
bark of the Saraca indica. 
The Saraca indica 4 is called in India the asok or asoka 
tree, and it is said when this tree is in full blossom, there is 
nothing in the vegetable kingdom which affords a more beauti¬ 
ful sight. Frequent mention is made of the plant in Hindoo 
mythology, and the bark is much used by native physicians 
in some diseases. 
1 Bureau of Statistics, 1885. 2 Crookes , p. 342. 
3 “On Hsematoxylin in the Bark of Saraca Indica ,” by Helen C. De S. 
Abbott. Proc. Acad. Nat. Sciences , Philadelphia, November 30, 1886. See 
p. 171. 
4 The Materia Medica of the Hindus , by Udoy Chaud Dutt. Calcutta, 
1877. 
