362 A Treatise on 
Gamboge readily takes Fire, and burns in a 
bright Flame, like a Refin, at the fame Time e- 
mitting a copious Smoke. It difiolves in Spirit of 
Wine, but not entirely •, for about a fixth Part 
remains undilfolved, to wit, the Gum, which is 
eafily loluble in hot Water, or in Oil of Tartar. 
It likewife difiolves in aqueous Menftruums into 
a whitifh or yellowifh Milk, but not perfectly ; 
becaufe the refinous Particles gradually concrete and 
fall to the Bottom of the VefTel, leaving the Water 
limpid. Whence it appears, that this Juice is a 
faline fulphureous, or refmous and gummous Con- 
crete, confifting of a thin Sulphur, which com- 
municates the Bitternefs and Smell to the Phlegm 
arifmg fir ft in Diftillation ; of a thick Sulphur, 
which is not raifed and feparated from the Earth, 
but by a ftrong open Fire *, and of a tartarous Salt 
fomewhat ammoniacal, which by the Means of 
Diftillation is refolved partly into an acid, and part- 
ly into an urinous Salt. The aqueous Solution of 
Gamboge, by pouring to it Oil of Tartar per 
deliquium , or Lime-Water, acquires a red Colour 
like Blood, by Reafon that the fulphureous Parts 
are expanded, as may be feen in a Diflolution of 
common Brimftone by a ftrong alkaline Lixivium. 
I am of Opinion, that the purgative Virtue of 
this Drug is owing to its thinner fulphureous Sub- 
ftance, mixed in a certain Proportion with vola- 
tile Salts •, forafmuch as thefe faline fulphureous 
Particles, being by the gaftrick Juice fet at Liber- 
ty and feparated from the grofier and fixt Prin- 
ciples, veiiicate the Membranes of the Stomach 
and Inteftines, enter the Pores of the Nerves, and 
irritate them : Whence a Naulea, Vomiting, and 
Purging. 
Some have fuppofed this Juice to contain a large 
Quantity of alkaline Salt, becaufe the Solution of 
it 
