236 AWiLYSm OF MTRRH. 



apmitransparent. Boilinpj water only divided it; but, on 

 adding gradually weak sulphuric acid to a very slight ex- 

 cess, the clots disappeared, and it was filtered. What re- 

 mained on the filter, when well washed and dried, consisted 

 of 5*3 gram. [81*8 grs.] of sulphate of lead, containinjr 

 4 gram. [6 1*76 ^rs.] of oxide; which had been combined 

 with l6 gram. [-247 grs.] of the gum, that were reobtained 

 by evaporating the liquor separated from the sulphate of 

 lead. This gum, which retained an excess of acid, yielded 

 neither malic nor phosphoric acid when treated with alco- 

 hol ; which led me to suspect, that the lime contained in 

 the gum of myrrh is saturated by acetic acid ; and perhaps 

 also by carbonic; for, if sulphuric acid be poured into a 

 •olution of this gum, a slight effervescence takes place, and 

 a precipitate of sulphate of lime. 



We see from what precedes, that the gum of myrrh is 

 not entirely separated from its solvent by the nitrate of 

 lead; since of the 23 gram. [355 grs.] only l6 [247 grs.] 

 fell down with the oxide. This must have been owing to 

 the nitric acid set free; for a salt of lead surcharged with 

 oxide, as the subacetate, precipitates almost wholly the so- 

 lution of the gum of myrrh, and entirely, if a little alkali 

 be added to the mixture. 

 The part inso- ^' What remained on the filter [B,] was heated with al- 

 luble ill water cohol, which dissolved all the resinous parts, and left be- 

 alcohol. hind a ioft, transparent, substance, insoluble in boiling 



water, and weighing when dried 6 gram. [92.6 grs.]. It 

 had all the properties of the gummy matter already men- 

 tioned. 

 Resin pro- E* The alcoholic solution (/>.), mixed with the spirit 



duced. used in washing the filters, yielded on evaporation 1 1*5 gram. 



[177*6 grs.] of a brown resin, with an aromatic bitter taste 

 like that of myrrh. 

 It"! properties. 1. This resin softens easily between the fingers, melts at 

 48" R. [140** F.], and does not become electric. 



2. It emits an aromatic smoke while burning, and yields 

 on distillation the same products as resins. 



3. With potash it forms a kind of soap, the aqueous so- 

 lution of which passes turbid through the filter. 



4. On 5*5 gram. [85 grs.] of this resin of myrrh were 



poured 



