Bell — On a Series of Bases derived from Pyrrol. 33 



III. — Ox A Series of Bases debited feoic Pteeol, axd some CoMPOuifDS 



ALLIED TO THEJI AND TO MlTCIC AciD. By ChICHESTEK A. BeLL, M.B. 



[Eead, January 22, 1877.] 



Since the discovery of pyrrol in coal-tar by Runge, and its subsequent 

 isolation by Anderson from the destructive-distillation products of 

 bones, few attempts seem to have been made to explain its chemical 

 constitution, or to ascertain its relations with other substances. This 

 is remarkable, because, for many reasons, its study is likely to prove 

 of interest ; and chiefly, indeed, because it is the simplest representa- 

 tive of that large class of nitrogenous bodies vrhose chemical history 

 "was, until quite recently, enveloped in complete darkness, and is even 

 yet by no means satisfactorily cleared up ; which form, as it were, the 

 connecting link between the true ammonia bases on the one hand, and 

 the hydrocyanic ethers or nitriles on the other, sharing as they do the 

 basic characters of the first, and the active toxic and physiological 

 properties of the second. I allude to such bodies as conine, nicotine, the 

 pyridine and chinoline series, etc. As an unstable body, also, pyrrol 

 claims our attention, for it may be laid down as a rule in chemical 

 research — at least so far as modern chemical doctrines are concerned — 

 that the more prone to change any substance is, the more fruitful in 

 theoretic results its examination is likely to prove. 



But while in itself pyrrol offers many points of interest to the 

 scientific chemist, its importance has been much enhanced by the dis- 

 covery, due to Malaguti and Schwanert,^ that it and a closely-allied 

 substance, the so-called carlo-pyrrol-amide, are the chief products ob- 

 tained when the ammonia salt of mucic acid, an acid easily obtained 

 by the oxidation of lactose (sugar of milk) or galactose, is exposed to 

 a temperature above 220° C. ; an importance which I venture to think 

 is much heightened by the observation made by my friend Dr. Edwin 

 Lapper and myself, that it is with stiU greater ease formed from 

 the ammonia salt of the isomeric saccharic acid, the principal oxidation 

 product of ordinary cane sugar, etc. The smoothness of the reaction 

 by which it is in both cases produced leads to the suspicion that it is, 

 in the true sense of the word, a decomposition-product of these salts, 

 and hence that it is intimately connected with them by molecular 

 relations. For these reasons I have undertaken the study of its 

 metamorphoses, etc., and as the first-fruits of my researches I beg to 

 lay before the Academy the results at which I have so far arrived. 



The reaction in virtue of which pyrrol is obtained from ammonium 

 mucate is very simple, and may be thus represented : — 



Ammonium mucate. Pyrrol. 

 Cs Hs (NH4)2 Os = C4H5N + NH3 + 2CO2 + 4HoO. 



1 " Annalen der Ctiemie und der Pharmacie," cxvi., 278. 



K. I. A. PKOC, SER. II., VOL. III. — SCTENCE. D 



