246 DIADELPHITA DECANDRIA. Butea. 
Sal martis changes the watery solution into a good durable 
inks? 
These are, I think, proofs that a very small proportion of 
yesin is present in this substance. In this it differs essentially 
from the gum-resin called Kino or Gummi rubrum astringens 
Gambiense, which the Edinburgh College has taken into their 
Materia Medica,* but as this can be most perfectly dissolv- 
ed in watery menstruum it may prove of use, where a spiti- 
tuous solution of the former, being the most complete, cannot 
be so properly administered; consequently it may prove a 
valuable acquisition also, I have used the recent gum in 
making my experiments, which may make some difference. 
Infusions of the flowers, either fresh or dried, dyed cotton 
cloth, previously impregnated with a solution of alum, or 
alum and tartar, of a most beautiful bright yellow, which was 
more or less deep, according to the strength of the infusion. — 
A little alkali added to the infusion, changes it to a deep red- 
dish orange. It then dyed unprepared cotton cloth of the 
same colour, which the least acid changes to a yellow, or le- 
mon. These beautiful colours I have not been able to render 
perfectly permanent. 
Amongst numberless experiments, I expressed a quantity 
of the juice of the fresh flowers, which was diluted with alum 
water, and rendered perfectly clear by depuration. It was 
then evaporated by the heat of the sun, intoa soft extract ; 
this proves a brighter water colour than any gamboge | have 
met with. It is now one year since I first used it, and it 
remains bright, 
Infusions of the dried flowers yielded me an extract very 
ae ifany rata inferior to this last mentioned, They _ 
tetéei of tin in n“ayna-regis ; but the reds produced thereby were 
bad ; that where alum was employed, was the best. 
* A specimen of the tree which produces this African substance 
in the Banksian herbarium, convinces me that it isa species: of 
aes desert pee. 
