918 SINAPIS. [class XV. ORDER H. 



beak, as long or longer than the valve. Seeds not very numerous, 

 globose, yellow. 



Habitat. — Waste and cullivateJ places; frequent. 



Annual ; flowering in July. 



This is the species usually cultivated and used when in a veryyouug 

 state, as an early spring salad, and is mostly joined with Cress, the 

 young plants of Lepidium sativum. The seeds of this and the follow- 

 ing species are used for making the mustard powder of commerce. 



According to the analysis of John, the seeds of the White Mustard 

 contain 



1. An acrid volatile oil. 5. A little gum. 



2. A yellow fixed oil. 6. Liquine. 



3. Brown resin. 7. Albumen. 



4. A very little extract. 8. Phosphoric acid and salts. 



From the experiments of Henry and Garof, the seeds contain a 

 peculiar acid, which has been named sinapin, and that upon it the 

 active properties of the seeds depend. 'I'he volatile oil is clearly 

 shown not to be formed in the seeds without the presence of water, 

 if the seeds are powdered, md then strongly pressed, the fixed oil is 

 obtained; and if the residue be distilled in an alembic, the volatile 

 oil is carried over with the water, and may thus be obtained in great 

 purity; this Dumas and Pelouze analyzed, and found to consist of 



Sulphur 20-26 



Carbon 40-53 



Hydrogen 5'02 



Azote l;3-4o 



Oxygen 11-74 



100-00 



The oil expressed from the seeds of Mustard has an amber colour, 

 is without smell, has but little taste, and is rather thicker than olive 

 oil. The seeds of the White Mustard produce about thirty-six per 

 cent, of oil, while that of the black give only about eighteen per cent., 

 but they contain more of the volatile oil; hence it will be seen that 

 ■when the Mustard is gi-own for the sake of the fixed oil, the S. alba is 

 the most productive; but when it is grown for the purpose of making 

 the Mustard Powder, the -S. nigra is the best. The fixed oil of either 

 of these species is excellent for the soap manufacturer, and is now 

 used in preference to the oil of rapeseed. The marce or cake left after 

 the oil is expressed from it, is much more acrid than it was in the 

 original condition, by the loss of so much bland tasteless matter, and 

 it is in that state powdered and formed into the common condiment, 

 known in the shops by the name of Durham Mustard. Besides being 

 rised as a seasoner of food, powdered Mustard is much used medicinally 

 in the form of a poultice, as a counter irritant in various affections ; and 

 as the irritating quality of the powder depends upon the presence of the 



