MUSTARD. 
201 
there would be no progression of the mass. Black mustard, 
independently of its very irritating properties, is too small. 
The extreme readiness with which white mustard gives with 
water an abundant mucilage (for which reason that having a 
thin perisperm should be chosen) adds to the facility, already 
very great, of the movement of the seed due to its convenient 
size and round form. Until the contrary is proved, it would 
appear that it is to this union of properties that white mustard 
owes its value as a purgative. 
The depurative properties of this seed do not appear so easy 
to explain, since it is rejected in the excreta apparently with- 
out having undergone any modification. But this appearance 
is deceptive. The penetration of a liquid into seeds which 
have not a thick perisperm is easy. By osmose a very rapid 
exchange takes place with uncontrollable force, between the 
liquid charged with the soluble substances of the seeds and the 
liquid that surrounds them. Moreover, we know by the law 
which governs dialysis, which has been so well explained by 
the late Mr. Graham, that membranes allow crystalloids to 
exude easily (sinapisine is a crystalloid) while they retain 
colloids (myrosine is a colloid). It is not impossible, then, 
that sinapisine should be rapidly carried off from the mus- 
tard-seed, although they remain intact, to be absorbed by the 
liquids of the digestive canal, and transferred by assimilation 
into the entire organisnr. That the sinapisine should be 
carried off as such, or that it should be transformed before- 
hand into sulphocyanate of sinapine, would matter little, 
sulphur being found in both substances. 
Sulphocyanate of sinapine is, without doubt, an energetic 
poisonous principle, but it is among such substances we find 
the most medicines. It is only necessary that the doses 
should be so suitably apportioned, that they may not ac- 
cumulate in the stomach, and that the elimination or destruc- 
tion should keep pace wdth the administration of a fresh 
quantity, without which there would soon be symptoms of 
poisoning. 
The less energetic character of black mustard, and its 
apparent inertness when employed as a condiment, should not 
be quoted in opposition to these views; for there the sul- 
phocyanic acid is not combined with a base but wdth an 
alcohol radical, forming the sulphocyanate of allyle, a very 
irritating substance ; not a salt, but an ether — that is to say, 
a substance absolutely different . — Journal cle Pharmacie et de 
Chimie. 
