594 PROFESSOR ANDERSON ON THE PRODUCTS OF THE 



close vessels it yields an oil of an extremely offensive odour, and which gives the 

 reactions of pyrrol, while a bulky charcoal is left in the retort. In the open air 

 it catches fire, and burns readily. When exposed to 212° in the water-bath, it 

 gains weight, owing to slow oxidation ; and the portion used for analysis was 

 therefore dried in vacuo. The results were — 



{6-381 grains of pyrrol red dried in vacuo gave 

 16'770 ... carbonic acid and 

 4-172 ... water. 



6 '440 grains of pyrrol red gave 

 0-846 ... nitrogen. 



{6-910 grains of pyrrol red gave 

 18-816 ... carbonic acid and 

 4172 ... water. 



{6-043 grains of pyrrol red gave 

 16-054 ... carbonic acid and 

 3-764 ... water 



y j 6-578 grains of pyrrol red gave 

 '\ ... nitrogen. 



{6-132 grains of pyrrol red gave 

 16-248 ... carbonic acid and 

 3-793 ... water. 





I. 



ii. 



in. 



IV. 



V. 



VI. 



Mean. 



Carbon, . . 



. . 71-52 





71-77 



72-45 



... 



72-20 



71-98 



Hydrogen, 



. . 7-29 





6-70 



6-66 





687 



6-88 



Nitrogen, 



• • • • • 



13-14 



• • • 





14-05 





13-58 



Oxygen, . . 









... 



... 



... 



... 



7-56 



144 



71-28 



14 



6-93 



28 



13-86 



16 



793 



100-00 



These results approximate most closely to the formula C 24 H u N 2 2 , which 

 requires 



24 eq. carbon, 

 14 ... hydrogen, 



2 ... nitrogen, 



2 ... oxygen, 



202 100-00 



It is true that the numbers obtained by analysis do not accord well with this 

 formula, and in particular the carbon is materially in excess, but this is undoubt- 

 edly due to a further decomposition produced by boiling ; for if the heat be con- 

 tinued for some time during its preparation, the red matter acquires a dark- 

 brown colour, and contains as much as 74 per cent, of carbon. The nature of 

 the change by which the red matter is produced is readily intelligible, and is 

 thus represented : — 



3 equivalents pyrrol, 

 — 1 eq. ammonia, 



+ 2 eq. water, 

 1 eq. pyrrol red, 



c 24 



H 15 

 H 3 



N 3 



N 





c 24 



H 12 

 H 2 



N 



o 2 



c 24 



H 14 



N 2 



° 2 



