530 PALMM. 



■ 



of iodine throws down brown drops, and picric acid a resinous 

 precipitate that afterwards crystallizes in needles. Gold chloride 



iwn 



oily drops, which, however, do not solidify. 



Platinic chloride, mercuric chloride, and tannic acid give no 

 precipitates. 



^ Arecaine (C^H'^NO^'H-O), purified by repeated crystal- 

 hzations from 60 per cent, alcohol, forms colourless crystals, 



permanent 



and in dilute 



alcohol, less soluble in stronger and nearly insoluble in absolute 

 alcohol, by which it is dehydrated. It is also insoluble in ether, 

 chloroform, and benzol. The aqueous solution is neutral in 

 reaction, and has a slightly perceptible weak saline taste. At 

 100*C. arecaine loses its water of crystallization, melts with 

 frothing at 213°C., and carbonizes when more strongly heated. 

 In a solution acidulated with sulphuric acid potassium-bismuth 

 iodide produces an amorphous red precipitate that very quickly 

 becomes crystalline. Potassium-mercury iodide is far less 

 delicate ;^ it ^does not precipitate the (neutral) solution of the 



e salt separates 

 precipitate that quicklj 



be 



crystallizes. Potassium iodide also fails to affect a neutral 

 solution, but upon acid being added dark-coloured needles 

 separate. Phosphomolybdic acid, as well as tannic acid, give a 

 slight turbidity; pic-ric acid gives no precipitate, and gold 

 chloride and platinic chloride precipitate crystalline double 

 salts from solutions that are not too dilute. 



Arecaine combines with acids to form crystalline salts, having 

 an acid reaction, freely soluble in water and less soluble in 



alcohol. 



H NO^H'O, isomeric withi arecaine, forms 



permanent 



soluble 



water and dilute alcohol, but almost insoluble in absolute 

 " "'■ ol, ether, chloroform, and benzol; it loses its water of cry- 



999 Z^l^^ ^* ^^^°^"' ^""^ ™^^*^' attended with frothing, at 

 : ;."^^ 0. ; It forms crystallizable salts and is precipitated by 

 platinic and aunc chlorides. Arecaine and arccaidine are 



stall 



