2 14 ^ Treatise on 
A Gum is a concreted Juice which eafily dif- 
folves in Water. In the Fire it neither melts nor 
flames, but only makes a crackling Noife. It is 
compounded of a fmall Portion of Sulphur com- 
bined with Earth, Water, and Salt, fo as to con- • 
flitute a Mucilage. Of this Sort are Gum Tra- 
gacanth, Arabick, the Gum of Plumb Trees, &c. 
and Manna. 
A Gum-Refin is a concreted Juice equally 
foluble in Water and in Oils, either wholly or in 
the greateft Part. It is compounded of refinous 
and gummous Parts united together. If with thefe 
there be a fufficient Quantity of faline Parts, the 
whole is intirely foluble in Water ; but if the 
Proportion of this Salt be not large, there re- 
mains in the Water fomething of a refinous Sub- 
fiance, which is only capable of being diflolved 
in Oil or Spirit of Wine. In this Rank are Bdel- 
lium, Myrrh, Aflfafoetida, Ammoniack, Euphorbi- 
um, Galbanum, Opopanax, Sagapenum, and Sar- 
cocol. 
We fhall now give an Account of fuch of thefe 
as are commonly prefcribed in Phyfick. 
Of Li qjj id Resins. 
A r t i c. I. Of the Balsam of Mecca or 
Balm of Gilead. 
Opobalfamum , Balfamelaon , Balfamum Judaicum , 
Gileadenfe , Syriacum , E Mecca , Conft ant inop olitanum^ 
Album , Off. ’ 07 to€ccX(tcc{aqv, Gracor. This is a pre- 
cious liquid Refin, of a whitifh Colour, or fome- 
thing yellowifh, having a fragrant Smell ap- 
proaching to the Smell of Citron, and an acrid 
aromatick Tafle. It ought to be chofen frefh, fluid, 
oily, and fragrant in its Smell * being not fo valu- 
able 
