SEMEN SINAPIS ALBJE. 69 



L 



into China from the latter region. Its cultivation in England is of 

 recent introduction, but is rapidly extending.' The plant is not 

 uncommon as a weed on cultivated land. 



History — White mustard was used in former times indiscriminately 

 with the brown. In the materia medica of the London Pharmacopoeia 

 of 17-0 the two sorts are separately prescribed. The important chemical 



Charlard 



mad 



Production — White mustard is grown as an agricultural crop in 

 Essex and Cambridgeshire. 



_ Description — Brassica alba differs from B. nigra in having the pods 

 bristly and spreading. They are about an inch long, half the length 

 being occupied by a flat veiny beak. Each pod contains 4 to 6 yellowish 

 seeds about ^ of an inch in diameter and yV of a grain in weight. The 

 brittle, nearly transparent and colourless testa encloses an embryo of a 

 bright pure yellow and of the same structure as that of black mustard, 

 ine surface of the testa is likewise pitted in a reticulate manner, but so 

 nnely that it appears smooth except under a high magnifying power. 



W hen triturated with water the seeds form a yellowish emulsion of 

 very pungent taste, but it is inodorous and does not under any circum- 

 stances yield a volatile oil. The powdered seeds made into a paste 

 with cold water act as a highly stimulating cataplasm. The entire seeds 

 yield to cold water an abundance of mucilaff 



=,e- 



Microscopic Structure — The epidermal cells of white mustard 

 attord a good illustration of a mucilage-yielding layer such as is met 

 ^'ith, under many variations, in the seeds of numerous plants. The 

 cuticle consists of large vaulted cells, exhibiting very regular hexagonal 

 *^f fV *^^ ^vhen cut across.' The inner layer of the epidei'mis is made up 

 ot thm-walled cells, which when moistened swell and give off the muci- 

 ^u{- 1 ^^^^ ^^^ staite or seen under oil, the outlines of the single cells 

 j>i this layer are not distinguishable. The tissue of the cotyledons is 

 loaded with drops of fatty oil and with granular albuminoid matter ; 

 u? T^^^^ ^s present in the seed while young, is altogether absent 

 ^ fien the latter reaches maturity. 



v' 1?^^"^^'^.'^^ Composition — White mustard deprived of fatty oil 

 . lelds to boiling alcohol colourless crystals of tiinalhin, an indifferent 



utjstance, readily soluble in cold water, but sparingly in cold alcohol. 

 rlT^\? a^le investigations of Will (1870) it follows, that it is to be 



egarded as composed of three bodies, namely : 



Sulphocyanate of Acrinyl ..... C' 

 gulphate of Sinapine C'^ 



H^ N 



S 



JJ25 J^ 



S 0' 



PJ12 



0« 



^^ that the formula 0*" H^ N^ S^ 0^* 



Sved^-^ ^^c^i'Jiiig to Will the composition of sinalbin. It is actually 



^ into these three substances when placed at ordinary tempera- 



(1855) 44Q ^y^^oped, of Ayriculturey ii. ^ An interesting object for the polarizing 



^^ourn 'dp ph .. microscoi^e. 



'^ePhann. xvii, (1831)279. 



