^^ CRUCIFER^. 



4 



yerized have a greenish yellow hue. Masticated they have for an 

 instant a bitterish taste which however quickly becomes pungent. 

 When triturated with water they afford a yellowish emulsion emitting 

 a pungent acrid vapour which affects the eyes, and has a strong acid 

 reaction. The seeds powdered dry have no such pungency. When the 

 seeds are triturated with solution of potash, the pungent odour is not 

 evolved ; nor when they are boiled in water. Neither is the acridity 

 developed on triturating them with alcohol, dilute mineral acids, or 

 solution of tannin, or even with water when they have been kept m 

 powder for a long time. 



, . , .^xe— The whitish pellicle already mentioned, 



which covers the seed, is made up of hexagonal tabular cells. The 

 epidermis consists of one row of densely packed brown cells, radia% 

 elongated and having strong lateral and inner walls. Their outer wal s 

 on the other hand are thin and not coloured ; they are not clearly 

 obvious when seen under oil, but swell up very considerably in ?«' 

 tZTJ ""' T'^^^'^S mucilage.i Seeds immersed in water become 



inpnn.r?-"'''''''?.'^'^^ ^ g^°^«3^ envelope, levelling down the superficial 

 St2w ' Z^^^^\ ^^" ^^t «^^d appears smooth. The tissue of the 

 cotyledons exhibits large drops of fatty oil and granules of albumin. 



ih. ^^Ti"^^^- Composition— By distilling brown mustard with water, 



musta 



is nrodiiPP.! nr, — ^. ' "'"^"^^'^i oii is not present in the dry seeu=, ■ 

 water the Ir^^^^ f H''^ ^^^^ ^^^^ comminuted and mixed vvv- 

 The rema^^^^^^^^ f ^^l^^ ^^^^^^ ^^t exceed 50° C. ^ , 



oil ;^ :SS^^tTl^^t ^-« -^to tlie fonnat^ <.f n^^J 



now called S»u„W« >*■ fT' ""='' *«™'''J MyroimU of fotam 



investigatious oTSe chemil „' "yarded, according to the admn 



tiit.se cnemists, as a compound of 



Sfer'? "^.^"^^ ^^- ^^«t^^-d oil . C^ ff NS 



^isuipiiate of potassium . . TT KS 



!^«gar (dextroglucose) 



H KS O* 



so that the formnln 7^ 



loimula ^,„ j^,3 j^^g, Qro 



is that of siuif^rin 

 subat '^ 



It does in fact split into the above-mentioned three 

 issolved in water and brought into contact with 



position of thilnL^n^fK''''*'''^^^^ ^y ^"««y in 1839, but the corn- 

 decomposition unde? tT: ■'' "^^"^^ ^"*' likewise undergoes a certain 



decomposed by alkak and' ^''T^^''^'^- ^^^^S"^ "^^^ ^^^^'""''^ /r 

 ' Most minutci according to Ludwig and Lange, by silv^^ 



\ 



^ Unttr- baues, i (Vienna, 1875U71— 202. 



