25 



ammonia a little more copiously than in tliose of otlier precipi- 

 tating agents. 



Belhldoiinill. Second alkaloid of Atropa Belladonna; it is 

 the yellow resin-like substance that prevents the crystallisation of 

 the atropin. Mode of isolation : Dissolve the crude atropin in 

 water by means of an acid, neutralise with carbonate of soda in 

 order to remove a fluorescent substance of bluish colour, filter 

 and add to the filtrate small quantities of carbonate of soda as 

 long as, according to the temperature and concentration of the 

 liquid, a conglutinating resinous or oily substance is formed. The 

 precipitation of a pulverulent body, occurring afterwards, has to 

 be avoided. Collect the precipitate on a linen cloth, rinse with 

 water, dissolve again in acid water, decolourise as much as possible 

 with animal charcoal, filter and, in order to prevent contamination 

 by atropin, precipitate as carefully as before with carlionate 

 of soda, collect, dissolve in absolute ether and evaporate. A 

 colourless or in thicker layers yellowish, gum-like mass, drying 

 with difliculty, of not very bitter, but burning-acrid taste, fuses 

 by heat and decomposes afterwards under emission of heavy 

 white fumes of the odour of burning hippuric acid; dissolves 

 readily in ether and in alcohol, little in water; of strongly 

 alkaline reaction; dissolves also readily in acids while saturating 

 them completely, but is less basic than atropin. Its sulphate 

 yields with ammonia a white pulverulent precipitate that becomes 

 soon glutinous, a property in which it resembles hyoscyamin. 

 Tannic acid also precipitates the sulphate of B. white. The solu- 

 tion of B. in weak alcohol is precipitated by nitrate of silver, 

 chloride of gold and bi-iodide of potassium. 



Beuic Aciclo C44 H43 O3 4- HO, In the oil of Behen, from 

 Moringa oleifera. The fat acids sepai-ated by hydrochloric acid 

 from the soap obtained by means of soda-ley are pressed and 

 the remnant crystallised in alcohol. Shining, white needles, 

 similar to stearic acid; fuse at 76^. 



Benzoic Aci(l=Ci4 II5 O3 -t- HO. Contained in large quanti- 

 ties in the benzoin and other aromatic resins and balsams, mostly 

 accompanied by cinnamic acid; in small quantities in different 

 odoriferous seeds and roots; often confounded with Cumarin, It 

 is obtained best and without much loss by boiling the respective 

 substance (finely contused when in a dry state) with milk of lime 

 and water, filtering, evaporating the filtrate, o versa turating when 

 cold with hydrochloric acid, collecting the crystalline deposit, 

 pressing, dissolving in the least possible quantity of hot water, 

 percolating, crystallising, collecting and drying. White lamina 

 and needles of mother-of-pearl lustre, mostly of faintly benzoic 

 odour and of slightly acid taste, which fuse at 120°, boil at 239°, 

 but begin to volatilise already at 145°, while emitting vapours 



