CHEMICAL BASIS OF T1IK ANIMAL BODY. _ul 



digo is decolourised, being reduced to indigo-white. The latter 

 contains two atoms of hydrogen nn>re than indigo, is ivcon\ 

 into indigo-blue by exposure to the air, ami thus piovi 

 convenient reaction for the detection of either indigo or of re- 

 ducing substances such as dexin 



r / NH \ i 



1. Skatol. C.H.N. CJV ;CH. .Methyl-indol. 

 L ^ C^ 



CH, 



Skatol was first noticed and detinitely described by Brit _ 



ring in human fares together with indol. the latter u-ually 

 being less in amount than the former. 1 Later researches have 

 shown that the conditions of it- production are in general the 

 -aim- as tlne for the formation of indol, so that the two sub- 

 -lance- iiccur mixed in variable proportions among the products 

 of the putrefactive decomposition of proteids 2 or brain-sub-tam-e '* 

 ami of the action of caustic potash at high temperatures on pio- 

 teid-. 4 In tin- former case it apjniars to be produced at a later 

 than i- imlol. -o that on tlie whole it is most preponderant 

 the longer the putrefactive change is allowed to proceed. Its 

 nee in the fares is thus due to causes similar to tho-e which 

 ace. milt for the presence of indol, and the resemblance is further 

 shown by the fact that a portion of the fir-t -formed skatol is 

 al. -orbed, oxidi-ed. and appears externally in the urine as ska: 

 sulphuric acid (see below). 



I is tWined in -mall ipiant itics during the preparation ! ind.,1 

 hv reduction f n. in indigo/' It may In- partly mm erted into indol by 

 j,a--i: !.iir- through a red-hot porcelain tube.* Tlie c'.n.-ti- 



tntin: I ua- f.ire>lial"\ved I -v its prepa rat ! ni fnnn the barium 



-alt- ,,i ..rtho-nitrociiniini,- a. -id. (< 'I I : ),< '1 1 . < . CiMir and 



clearlv proved bv it- -\nthetic pi-.idiictinii fn.ni pn>p\ lidcne-pheny lliv- 

 drax.i \II . N ' CII . Ml.. <'H 3 , the ],r.,durt ..f the ai-ti.ui ..f 



aldehyde (CH, . CH.. '< Ml ) on phenylhydra/in ((',11 .Ml. 



ttrr. tl. ,1. cl.rm. Crs,!!. TM. X. (IS7T). S. 10a;. .In f. /. 

 IM xvii. .1-"- > l.'l A dOMlj >iinil;ir. if not i.li-iitirul. stil^tui. 



n.itirfil. I. lit nut rli-:irh rli:ir:u trri"'<l. l.v Nni.-ki. :i- ainniiir the 



]ir<M|in-t ( flu- |.utr t i MijHi-iii ..... .f ir'l:itiu. ami ! .iiimni; tli-i- 



'nilar iliTniiii<>.iiiiiii <>( pr-' 



'nilar iliTniii|i< 



/. </. i/,../. if-- i-:-. s - i: ii 11 s:iik,..-ki 



IM.'xii. (is: H'l MII (1884), 



S. 417 4t",r,. Ci.iitaiii-* V.TV full n-l". previous lid-nittire. 



n.-ki. /'.../. IM. IV. (1880), 8. 371. St.,rklv. .In I j.r.dt. C/.tm. (1 

 15.1. \\iv (I--I). S. 17. 



IM. xvii. (IH7SI. E 

 s IV, xui. (issfi). S. 2339. 



' ', , 1. xiu. (18&3). j.. :i7x. S btr. in Ber. rf. /. chtm. 

 Gr*'<l I" - 



t K. p. 356. AbLloc.e,t 



