490 M. H. Bleibtreu on Cumarine. 



The determination of the hydrogen, on which the formula 

 more directly depended, leaves no doubt as to the choice 

 of the two. The formation of nitrocumarine is analogous to 

 that of nitrobenzole, nitrostyrole, &c. : — 



C ]8 H 6 4 + HO,N0 5 =C ]8 |^5jo 4 + 2HO. 



Cumarine. Nitrocumarine. 



I have but little to add to Delalande's description of the 

 properties of this body. Nitrocumarine dissolves with diffi- 

 culty in water, alcohol and aether, and crystallizes in fine 

 needles from these solvents as soon as the temperature falls 

 a little below their boiling-point. Its point of fusion is about 

 170° C. ; heated beyond this it sublimes without decompo- 

 sition in the form of large white crystals of the lustre of 

 mother-of-pearl. 



Nitrocumarine forms with alkalies a solution of a deep 

 yellow, almost red colour, which disappears on the addition 

 of an acid, with separation at the same time of a white cry- 

 stalline matter. This reaction was further examined in the 

 hopes of obtaining an acid corresponding to nitrocumarine, 

 viz. the nitrocumaric acid. 



For this purpose nitrocumarine was boiled for some time 

 in an alcoholic solution of potassa; the potassa compound 

 formed, decomposed by hydrochloric acid, and the precipitate 

 after removal by washing of the chloride of potassium, re- 

 crystallized from boiling alcohol. 



To free the crystals (which I regarded as nitrocumaric acid) 

 from any nitrocumarine which might still be mixed with 

 them, they were dissolved in ammonia, and on boiling, to re- 

 move any excess of the latter, a portion of the substance was 

 deposited in the form of white crystalline flakes. That these 

 crystals were only cumarine was proved by the absence of 

 any trace of ammonia on heating with potassa. 



The filtered solution, which was neutral, gave with nitrate 

 of silver a beautiful orange-yellow colour, with acetate of 

 lead an orange precipitate. Both compounds were soluble in 

 a considerable quantity of water, forming a lightish yellow 

 solution, but less so in alcohol and aether; so that they could 

 be purified by boiling in these menstrua. I have analysed 

 these compounds as well as the substance separated from 

 them by acids. 



The lead and silver precipitates are direct compounds of 

 nitrocumarine with the oxides of the metals, and the electro- 

 negative bodies obtained from them is pure nitrocumarine. 



