97 



destroyed in higher temperatures, dissolves in 7 parts cold and in 

 5 parts boiling water, in 3 parts cold and 2 parts boiling alcohol, 

 in 1700 parts cold and in 1100 pai-ts boiling ether, readily in 

 liquor of ammonia, in concentrated sulphuric acid with brown- 

 red colour; secedes on heating with diluted acids or alkalies iiito^ 

 sugar and some other product. 



Green Acid. Occurring in the roots of many Dipsacege, Com- 

 posite and Umbelliferse, forming with ammonia a yellow com- 

 pound which becomes blue-green at the air, resembles cafFe-tannic, 

 rubichloric and valeria-tannic acids. Exhaust (say, the root of 

 Scabiosa succisa) with alcohol, precipitate the tincture with ether, 

 collect and wash the white precipitate with ether, and throw down 

 its aqueous solution with acetate of lead. After this precipitate is 

 decomposed under water with sulphui-et of hydrogen and the 

 filtered liquid evaporated, the green acid remains as an amorphous, 

 yellow, brittle, acid mass. 



GUilCill. Resinous bitter substance of the leaves of Mikania 

 Guaco (and perhaps other Guaco-plants), Draw out with ether, 

 ti*eat the ethereous extract with alcohol, the alcoholic extract with 

 boiling water, the aqueous extract again with alcohol, and evapo- 

 rate the latter solution to dryness. — Yellowish-brown, resinous, 

 very bitter, fuses at 100°, dissolves very slightly in cold, abun- 

 dantly in boiling water, most readily in alcohol and ether. 

 . Guaiacic Aci(l=Ci2 Hg Og. In the wood and resin of 

 Guaiacum officinale. Dissolve the resin in alcohol, concentrate the 

 solution to one-quarter its volume, separate after cooling the acid, 

 yellowish liqxiid from the subsiding resin by filtering, evaporate 

 the former to a syrup-consistence, exhaust with ether, evaporate- 

 the solution and sublimate the acid from the obtained warty mass 

 containing resin over a carefully-conducted fire. — White, shining, 

 neadle-like crystals, much more soluble in water than benzoic or 

 cinnamic acids, also soluble in alcohol and ether. Requires 

 further comparisons with benzoic acid. 



Guaiaconic Aci(l=:C38 Hoo Oio. Constitutes about 70% of 

 guaiacum resin. An alcoholic solution of guaiacum resin is mixed 

 with an alcoholic solution of caustic potash; the liquid is separated 

 from a solid product, consisting of acid guaiacum resin and potash,, 

 and evaporated at a temperature of 30°. A thick syi'up-like fluid 

 remains, which naixes with absolute alcohol under separation of 

 some acid guaiacum resin combined with potash. Remove the 

 mass, pervade the liquid with carbonic acid, filter, mix the filtrate 

 with water and a little hydrochloric acid, evaporate the alcohol, 

 and wash the resin thus obtained with warm water. It appears, 

 after drying, as a brittle, brown mass. This resin, by treating 

 with ethei', is decomposed into Guaiaconic acid, which dissolves, 

 and into guaiacum beta resin remaining undissolved. Separate 



H 



