38 . Proceedings of fhe Royal Ii'ish Academy, 



The liquid of low boiling point, after a fe-v\^ rectifications, distilled 

 at 131°, and on analysis yielded tte following results : — 



Experiment. Calculated for 



I. II. III. CiSilCoHs)^. 



C = 75-92 — — 75-79 



H = 9-71 — — 9-47 



Is" = — 14-58 14-69 14-83 



That it was an ethyl-deiivative of pp-rol is thus proved by its 

 analysis, and the eii'cumstances under which it was produced. 



Ethyl-pp-rol is a colourless liquid of sp. gr. '9042 at 10°C., -8936 at 

 1 5° C. It possesses an odour closely resembling, biit still distinguishable 

 from that of pyrrol. Like that body, it is very spaiingly soluble in cold 

 water or in dilute acids, easily in concentrated hydi'ochloric, nitric, or 

 acetic acids. Sulphuric acid also dissolyes it, giying a dark-coloured 

 solution which strikes a deep black with potassium bichi'omate. Its 

 rapour, like that of pyiTol, colours fir-wood moistened with hydro- 

 chloric acid an intense crimson. "With alcoholic mercuric chloride it 

 gives a white precipitate. Its alcoholic solution gives a dark colour 

 with platinum tetrachloride, biit no precipitate, even on standing f or- 

 twenty-four hours (difference from pyiTol). 



By their behaviour with concentrated acids the two bases are 

 strikingly distinguished. When pyrrol is boiled with strong hydro- 

 chloric acid, it is converted in a few seconds into a jelly-like mass of 

 pyiTol-red ; whereas the ethyl-derivative may be boiled for some time 

 with the concentrated acid, and aftei'wards, by dilution, precipitated 

 unaltered. Both pyrrol and ethyl-pyrrol are oxydized with explosive 

 violence on gentle warming with strong nitric acid ; and in the cold 

 the former is quickly converted into pyrrol-red. But if ethyl-pyiTol 

 be dissolved in a minimum of cold nitric acid, the mixture on standing- 

 for some time deposits a thick, oily liquid, which may be redissolved 

 by a slight addition of acid, only to reappear soon. "When freed fi'om 

 nitric acid and pyrrol, by washing with water, this liquid does not 

 give the fii'-wood reaction, either alone or when heated with potash. It 

 is in all probabihty a nitro-derivativc. I propose to examine it 

 further. 



If bromine be added to ethyl-pyrrol or to its solution in ether, 

 chlorofoi-m, acetic acid, etc., the mixture becomes black and tarry, 

 giving ofi hydi'obromic acid. But if a fi'eshly-prepared and cooled 

 solution of bromine in alcohol be cautiously added to an alcoholic 

 solution of ethyl-pyrrol, at a certain point, the latter deposits ciystals 

 of a compound, melting about 90° C, quite insoluble in water, and 

 but sparingly taken up by strong spirit. It is probably an addition 

 product ; but I have not yet obtained it in sufiicient quantity to 

 examine it completely. I'nder no circiimstanccs have I been able to 

 obtain such a body fi'om pyrrol. 



The liquid boiling at 269*^-270°, when pure, solidifies slowly to a 

 mass of loug and thick prisms, which arc more rapidly but not sa 



