29 



lieat tmder loss of watei' and decomposed in higher temperatures. 

 It is of an intensely bitter taste, dissolves in 800 parts water, 

 most readily in alcohol, not in ether, easily in chloroform, in 70 

 parts of glycerin, very little in volatile, still less in fixed oils, 

 without colour in concentrated sulphuric acid; with rose-red 

 colour in chlorine- water, and changing to a dirty-yellow by ammonia 

 without turbidity. Nitric acid yields a vividly red solution, which 

 becomes yellow on warming, and is coloured purple-violet and 

 precipitated by subchloride of tin. 



Bl'yonill=C96 Hso Oss. The bitter substance of the root of 

 Bryonia alba. Ti-eat the alcoholic extract of the root with cold 

 water, precipitate the solution by acetate of lead, filter, remove 

 from the filtx-ate the lead by sulphuret of hydrogen, neutralise 

 with carbonate of soda, precipitate with tannic acid, dissolve the 

 precipitate in alcohol, and mix intimately with hydrate of Lime, 

 digest, filter, decolourise with animal charcoal and evaporate. 

 Colourless, very bitter substance, friable to a white 2:)0wder, dis- 

 solves readily in water and alcohol, not in ether; yields with 

 diluted acids sugar and other products. 



BuplltlialllUini Stearopteil. Obtained by distilling the 

 flower's of Buphthalmum salicifolium (of a pleasant roselike odour) 

 with water and cooling the distillate to 0°, at which temperature 

 the stearopten separates. Yellow, silky, pointed crystals, melting 

 by the warmth of the hand to a yellowish oil of a faint but 

 pleasant odour, of faintly acid reaction, readily soluble in alcohol. 



Butyric Acid =C8 H7 O3 + HO. Asyetonlyfoundinthepulp 

 of the fruits of a few trees — Cei-atonia Siliqua, Sapindus Saponaria, 

 Gingko biloba, Tamarindus Indica — but imdoubtedly widely diflused 

 throughout the vegetable kingdom. It is obtained by distilling the 

 respective substances with water containing a little sulphuric or 

 phosphoric acid. The distillate, in which the presence of butyric 

 acid may by the odour of rancid butter be easily detected, 

 has to be mixed with carbonate of baryta ; concentrate ; filter 

 when of neutral reaction, and bring to dryness. The remnant 

 (butyrate of baryta), when dried at 100°, is anhydrous, and contains 

 f)0-77% acid. In order to isolate the acid, the salt is dissolved in 

 three parts of cold water, mixed with one-third of its weight of 

 concentrated sulphuric acid, well stirred, filtered ofl' from the 

 sulphate of baryta and rectified. In oi'der to remove traces of 

 water, the acid has to stand for some days over chloiide of 

 calcium, and is then decanted and rectified. 



Colourless liquid of a penetrating smell of rancid butter and 

 acetic acid and of strong and pungent sour, afterwards sweeti.sh 

 taste, has a density of 0-96 to 0-98, boils at 164°, is inflammable, 

 mixes in every proportion with water, alcohol and ether. Its 



