M. H. Bleibtreu on Cumarine. 489 



that a corresponding change would likewise require to be 

 made in that of the product of decomposition. 



Cumarine dissolves without almost any evolution of red 

 fumes in cold fuming nitric acid, and with considerable ele- 

 vation of temperature. On addition of water a white cheesy 

 precipitate is obtained, which quickly settles to the bottom. 

 The fluid possesses a deep yellow colour. After washing 

 with cold water, the precipitate was dissolved in boiling al- 

 cohol, from which, on cooling, white shining silky crystals 

 separated. In this treatment with nitric acid a strong heat 

 is to be particularly avoided, as the whole of the cumarine is 

 converted into nitropicric acid if the fluid is allowed to boil. 

 The formation of a small quantity of the latter acid can never 

 be completely avoided, and from this cause arises the yellow 

 colour of the mother-liquor. 



To the above product of decomposition Delalande gave the 

 name nitrocumarine, and the following formula derived from 

 his view of the composition of cumarine : — 



C]8 



\N0 4 / U 4- 



It is scarcely necessary to remark that this formula must 



be changed into 



^18 



\N0 4 / U4J 



as is shown by the analysis of the fused crystals with oxide 

 of copper. 



0-5675 grm. of substance gave 1-1657 carbonic acid and 

 0-1348 water. 



In per-centage, — 



Carbon 56-02 



Hydrogen .... 2*64 



which, compared with the per-centage calculated from the 

 new formula, is 



Theory. Experiment. 



( *~ \ 



18 Carbon . 1350-00 56-54 56-02 



5 Hydrogen 62-50 2-62 2-64 



1 Nitrogen . 175-25 - 7'34 



8 Oxygen . 800-00 33-50 



2387*75 100-00 



Delalande's formula requires the following per-centage : — 



Carbon .... 56-24 

 Hydrogen ... 3*12 

 Phil. Mag. S .3. Vol. 29. No. 1 96. Dec. 1 846. 2 L 



