72 CRUCIFER^. 



often almost cylindrical, throwing off here and there filiform and long 

 slender cyhndrical roots, and finally dividing into two or three hranches. 

 iiie root is^of a hght yellowish brown; internally it is fleshy and 

 per ectly white and has a short non-fibrous fracture. Before it is 

 broken it is inodorous, but when comminuted it immediately exhcales 

 ts chamctenstic pungent smell. Its well-known pungent taste is not 

 lost in the root carefully dried and not kept too long. 



A transverse section of the fresh root displays a large central 

 column with a radiate and concentric arrangement of its tissues, whicli 



^IcuTFT^y ^^ ^ T""^} ^''^y'^'^' ci^-cle from the bark, whose breadth is 



om 3, to -lines. ^ In the root branches there is neither a well-defined 



Ubei nor a true pith. The short leaf-bearing branches include a large 



sCn'rr?^ ^? ^ '"'^^^ ^f ^^°dy bundles. The bark adheres 



easHv n.v.° ^l^''^/■f P"^'^^*^^' ^^ ^hich zones of annual growth are 

 easily perceptible, at least in older specimens. 



tabaw'c^fl?^'" Stmcture-The corky layer is made up of small 

 the midd?p\''VTv'\'^ '^}'''^''' ^^^^'- In the succeeding zone of 

 pare^chvnl .T'''/ '^V^^F'^ ^^^^^^^ ^e"« ^^'^ scattered through the 

 ?oot the^ci^in/r^ ^ ^^' boundary line of the corky layer. In the 

 whLtTn Tts W T'^T ^^ °^* strikingly separated from the liber, 

 shaped l?ber b^^^^^^ '^'' separation is well marked by wedge- 



Ion SSllv.^nl' 7^'' ^"" accompanied by a group of the yellow 

 sho? y^^^^^^^^^ «tone ceUs. The woody bundles contain a few 



prope.?r voody i^'^^r"'."^^ ^""1^^^ ofprosenchymatous, iiot 



bundles to be semrat^H hX ''''^f ', '^ ^^'^ ^«°t' ^^^^^^ ^^''' ^'i^' 

 the central rnln? -^ ^^^ medullary parenchyma ; in the branches 



the lattei forW Toft '^^ ^"^^^^^ P^^^ ^'^'^^^^ -^^^^ ^^^^^^^' 

 of the whole root ool.' /.^'' *^ ^^'^ cambium. The parenchyma 

 granules. '^^^""^"'^ ^^ ^P^ing is loaded with small starch 



root (th? dremfcarhkfi^'°''7'^I''°"g ^^^ constituents of horse-radish 

 volatile oil isThe mni^ ? ""^ ^^^^^"^ ^« ^o^^^^ver far from perfect) the 

 tillation with wed^TV^^T^'""^- The fresh root submitted to dis- 

 which is identical with ?!,%'?. ^',*'^^*' ^^^^^^ ^^^^t i per mille of oil 

 Hubatka. He coJb-n.i^f ^^^^^^k Mustard as proved in 1843 by 

 thiosiuammine theomnr.-!-^'''^^i'^"*n'^^^a and obtained crystals ot 

 from mustard oil. """"'P^^^^'on of which agreed with the thiosiiianimuie 



^sttSw^td' nl.^?:^' i^ ;^--^ ?'. the odour; ofthe oU^ 



The essential oil dop, + u^''''' °^^^ ^^"^sioa of F/w^6 Mustard, 

 (inyronateofpotassinm^o 1 ^^f^fore pre-exist, but only sinigno 

 mutual reaction in tb^ rf """^ albuminoid matter (myrosin) by whose 

 Proce.. does not L o^ inT'' '^ ^^^^^^' ^^ i« farmed (p. 66). This 



^pther in some condition fL?i'''''^^ ^^ ^^e same cells, or 

 other,-a state of thim^ «.^f '^''' ^^^ ^"ow of their actin 





exhausting 



g 



in the leaves of 



ia decomposed and a cousMpTIS "'"'^'' ^'^^^' «old or hot, the sinigrjn 

 the concentrated decoction a| ^T'^''''' ^^ bisulphate is found m 



Alcohol removes from the root some fatty 



