172 



witli aid of animal charcoal. — Forms white, silky, often concentri- 

 cally united needles of bitter, then sweetish taste, and of neuti'al 

 reaction ; loses the water at 100°, fuses at 109° to a colourless 

 resin, becomes hard again at 130°, fuses again at 158° to 160°, and 

 becomes decomposed with more heat; dissolves in 833 parts cold 

 water, most readily at 50°, and in eA^ery proportion in boiling water, 

 readily in alcohol, wood spirit, acetic acid, very little in ether, in 

 wai'm concentrated sulphuric acid under decomposition with a red 

 colour; breaks iip, on heating with diluted acids, into grape-sugar 

 and phlorrhetin (C30 H14 Oio); becomes with ammonia successively 

 orange-red, purple and dark blue. 



Pliysalin=C28 Hxe Oio. The bitter ingredient of the leaves of 

 Physalis Alkekengi. Exhaust with cold water, add to 1 liter of 

 the liquid 20 grammes of chloroform, shake with two changes of 

 the latter, evaporate the chloroform, dissolve the remnant in hot 

 alcohol, shake with animal charcoal, thi'ow down the filtrate with 

 water, wash the deposit and dry. — Voluminous, white, or slightly 

 yellowish powder, becomes electric by friction, not crystalline; 

 of at first slight, afterwards lasting bitter taste; softens at 180°, 

 becomes plastic at 190°, decomposes afterwards, dissolves very 

 little in cold, a little more in boiling water, readily in alcohol and 

 in chloroform, little in ether, very little in diluted acids, readily in 

 liquor of ammonia. 



PliySO(lill=C24 H12 O16. Crystalline resin of Parmelia phy- 



sodes. Draw out with ether, evaporate, wash the remaining white 

 powder with alcohol, and recrystallise in boiling anhydrous 

 alcohol. — White, loose mass, consisting of microscopic needles (or 

 larger crystals by spontaneous evaporation), neutral, fuses at 125°, 

 behaves to water like a resin; is insoluble in alcohol of 80%, dis- 

 solves in boiling absolute alcohol, not in ether, acetic acid, readily 

 in the hydrates and carbonates of alkalies. 



PbySOSti«'iniu=C3o H21 N3 O4. Alkaloid of the Calabar 

 bean ' (Physostigma venenosum). Mix the newly prepared 

 alcoholic extract with an excess of bicarl)onate of soda, shake the 

 solution with an adequate quantity of ether, treat the ethereous 

 solution with a very diluted acid, separate the acid solution com- 

 pletely from the ether, drive oif the ether which has dissolved in the 

 aqueous solution, filter through wet paper, add an excess of bicarbo- 

 nate of soda, shake again with ether and evaporate the latter. — Forms 

 colourless, rhombic laminse*; fuses at 45°, becomes slightly decom- 

 posed when kept for a longer time at a temperature of lOO''; dis- 

 solves readily in alcohol, ether, benzol, sulphide of carbon, chloro- 

 form, less readily in cold water; is of strongly alkaline reaction, and 

 neutralises the acids completely. When divided under water, and 



* VC-e describes the Ph. as rhombic leaflets, fusible at 69°. 



