98 



the acid iii tlie ethereous solution with potash-ley, throw away the 

 supernatant ether; dilute the alkaline solution with water, and thi'ow 

 down with acetate of lead. The grey-gi'een precipitate is decom- 

 posed under water with sulphuret of hydrogen; the deposit is dried 

 and extracted by alcohol, which dissolves the Guaiaconic acid and 

 leaves it on evaporating. — Light-brown, brittle mass of concheous 

 fracture, friable to a paler, inodorous, and tasteless powder ; 

 neutral; fuses at 95° to 100°, and decomposes afterwards; is 

 insoluble in water, readily soluble in alcohol, ether, acetic acid, 

 chloroform, scarcely in benzol and sulphide of carbon, in concen- 

 trated sulphuric acid with beautiful cheny-red colour, and 

 precipitable from it by water in violet flocks, containing sulphur. 



Giiaiacuiii Beta Resin =C4o Hoo O12. Constitutes 10% of 



guaiacum-i'esin. Is obtained dui-ing the preparation of guaiaconic 

 acid, and forms the residue insoluble in ether ; ^vithdraw from it 

 all guaiaconic acid by treating the substance mixed with sand 

 with ether, dissolve in alcohol, decolom^ise with animal charcoal 

 and precipitate by pouring the solution into ether. The brown 

 flocks are purified by dissolving anew and precipitating, and 

 lastly dissolved in alcohol and again separated with water. — Red- 

 brown powder, neutral, fusing at 200° to a black mass, is insoluble 

 in water, readily soluble in alcohol and alkalies, not in ether, 

 sulphide of carbon, chloroform, and benzol. 



Guaiacnni Yellow, Yellow pigment of guaiacum resin. Boil 

 the pulverised resin with caustic lime, filter, evaporate the liquid, 

 in order to remove most of the lime as carbonate, and with it 

 most of the acid guaiacum resin ; extract the remnant with water, 

 oversaturate the solution with acetic acid, filter again, and allow 

 to stand for a rather long time. Small, pale-brown, tabular crystals 

 are formed, which dissolve slowly in much water, while leaving a 

 resin ; readily soluble in ether and alcohol, and crystallising- in the 

 latter on evaporating at ordinary temperature. — Pale-yellow, 

 quadratic, octahedrons, or tabular crystals, iiiodorous, bitter, fusible 

 by heat and afterwards decomposing, sparingly soluble in water ; 

 soluble in alkalies and alkaline earths, in alcohol, ether, sulphide 

 of carbon; difficultly in chloroform, benzol, oil of turpentine; 

 scarcely a little in acids. 



Guaiacillll Resin. From the stem of Guaiacum officinale, 

 ]iartly exudating spontaneously, partly obtained by extracting 

 with alcohol. Is greenish outside, inside reddish or greenish- 

 brown, brittle, grey-white when pulverised, turns greenish at the 

 air, has a balsamic odour, and a sweetish-bitter taste which is at 

 the same time acrid and irritating to the throat ; dissolves readily 

 in alcohol, 90% in ether (the beta-resin is insoluble); readily in 

 alkalies and re-precipitable by acids ; fuses easily, and burns after- 

 wards with a strong aromatic smell. The tincture turns blue 



