CHAP. X.] PHENOL AND PARAKRESOL. 433 



which, as Nencki had shewn, does not yield indol as a product of 

 bacterial decomposition, also furnishes no phenol. Brieger 1 shewed 

 that the excrements contain a phenol. 



Baumann's Mixtures of albumin and pancreas are digested in 



he- the incubator at a temperature of 40 C., from 3 to 



- 



noifrom pro- ^ c - c ^ a solution of ammonium carbonate being added 

 ducts of putre- to each litre. After 6 days' digestion, the liquid product 

 faction. is distilled, and the distillation continued so long as the 



distillate becomes distinctly turbid on the addition of bromine water. 

 The strongly alkaline distillate is shaken up with one-half to three- 

 fourths its volume of ether and the ethereal solution, having been 

 collected apart by means of a separating funnel, is distilled. The 

 residue is treated with caustic alkali and water and again distilled. 

 The distillate consists of water, ammonia, indol and skatol. As soon 

 as no more indol distils over, the residue in the retort is neutralised 

 as carefully as possible with sulphuric acid and again distilled. The 

 distillate, which contains the phenols, is abundantly precipitated on 

 the addition of bromine water, and the precipitate very soon becomes 

 crystalline, the crystals presenting the appearance of fine needles. 

 If, instead of precipitating with bromine water, the distillate is shaken 

 up with ether and the ethereal solution is evaporated, a residue is 

 obtained which, when the pancreatic glands of several oxen have 

 been employed, consists of some drops of an oily liquid; these possess 

 an obvious smell of phenol and exert a caustic action when applied 

 to the skin. When dissolved in water, the solution gives with ferric 

 chloride a blue-violet colouration, and with ammonia and a particle 

 of bleaching powder a beautiful blue reaction. Baumann recognised 

 that the phenol thus obtained was not pure, and stated that, when 

 precipitated with bromine, the tribromophenol obtained contained 

 more than the theoretical quantity of bromine. 



Baumann As it had been shewn that the urine of the 



^ orse con tamed the potassium salt of parakresol -sul- 

 the P nur i c a cid as well as that of phenol-sulphuric acid, it 

 products of pu- appeared likely that, in the process of putrefaction of 

 trefaction. proteids, parakresol might be produced. A research 

 conducted by E. Baumann and L. Brieger proved the accuracy of the 

 surmise 2 . Subsequently, working under Baumann's direction, Weyl 

 succeeded in obtaining both parakresol and phenol by the putre- 

 factive decomposition of tyrosine 3 . 



1 L. Brieger, ' Ueber die fliichtigen Bestandtheile der menschliclien Excremente ' 

 (aus d. Laborat. von Prof. Nencki), Ber. d. d. chem. Gesell, Vol. x. (1877), p. 

 1027 et seq. 



2 E. Baumann und L. Brieger, 'Ueber die Entstehung von Kresolen bei der Faulniss,' 

 Zeitsch.f. phys. Chem., Vol. in. (1879), p. 149. 



3 Th. Weyl, ' Spaltung von Tyrosin durch Faulniss,' Zeitsch. f. phys. Chem., Vol. in. 

 (1879), p. 312. 



G. 28 



