174 



FOODS AND FOOD ADULTERANTS. 



The acrid principle of wLite mustard appears to possess but little stability, 

 and although it is stated by V. Babo to bear a temperature of 130C., we find that it 

 is readily affected by heat, and that it is not safe to evaporate the alcoholic solution 

 containing it at a higher temperature than about 30C. If subjected to a much 

 higher temperature it quickly loses its acridity and acquires a bitter caramel-like taste. 



Of neither brown nor white mustard had any percentage analysis been given until 

 those made and published by ourselves in an article on mustard and its adulterations, 

 in " Food, Water, and Air," for February, 1874 ; and in the few cases in which the quan- 

 tities of any of the constituents are stated, they vary greatly according to different ob- 

 servers. Thus, according to Pereira, the fixed oil forms about 28 per cent, of the seeds 

 of black mustard, while Watts puts the yield at 18 per cent, only, but white mustard 

 seed, he says, furnishes 36 per cent. The volatile oil amounts to 0.20 per cent. , accord- 

 ing to Boutron an d Robiquet ; 0.55 per cent., according to Aschoff, and 0.50 per cent, 

 according to Wittstock ; all of which quantities are much below the mark, as will be 

 seen hereafter. Now, as will be shown presently, there is little or no difference in 

 the amount of fixed oil furnished by the two descriptions of mustard, that obtained 

 by me from the farina of brown mustard reaching 35.701 per cent., and that from the 

 white mustard 35.768 per cent. Again it is shown by the analyses given below that 

 the volatile oil occurs in much larger quantities than those enumerated above, the 

 amount which we have obtained from one sample being no less than 1.271 per cent. 



Of both brown and white mustard we append the following original percentage 

 analyses, first published in the article referred to : 



BROWN MUSTARD FARINA. 



The oil extracted by ether from the brown seed is of a bright and beautiful emerald 

 green color, owing to the presence of the peculiar green principle described as one of its 

 constituents. So deep and remarkable is the color of the oil that it would be easy, 

 by means of a graduated scale of tints, to determine with very tolerable certainty 

 the percentage of brown mustard contained in any samples of mixed mustard. 



WHITE MUSTARD FARINA. 



