126 



Chocolate as they deserve, and are scarcely prepared to expi'ess an 

 opinion with I'egard to Dr. Hassal's report upon them, -which is to the 

 effect that only 8 samples out of 56 were genuine ; in 43 he found from 

 five to fifty per cent, sugar, and in 46 a similar proportion of starch — 

 potato starch in some, and various mixtures in others. In all the 

 samples we have examined we find abundance of starch, chiefly potato 

 and wheat, and in some a large amount of sand. 



Mustard is a substance of very extensive and daily consumption, 

 and is subject to wholesale adulteration, hut for what reason we are at 

 a loss to guess, unless it be indeed to accommodate the pubhc with a 

 bright and pretty looking article at a low price. 



The detection of the adulterations of mustard is very simple by the aid 

 of the microscope. The characters of the seed are exceedingly distinct. 

 It is composed of several membranes differing from each other, in the form 

 of their cells. The external membrane is composed of large colourless 

 angular cells, in the centre of which is an apparent nucleus cell, but 

 which, on more close observation, resolves itself into a simple hair, 

 arising from the folds of the cell membrane ; these cells are filled with 

 mucilage, which, on being moistened, swells and fills out the cell. The 

 membrane immediately beneath this consists of a single layer of angular 

 or rounded cells, having a very decided central nucleus ; they adhere 

 firmly to each other, and form a consistent membrane. These two 

 membranes form the most characteristic features of the mustard seed, 

 the remainder being composed of cellular and vascular tissue filled with 

 oil globules. Starch grains are very rarely found, especially if the 

 seeds be fully ripe. 



We have examined many samples of mustard floux', as served to the 

 public, but in all we have found an enormous quantity of wheat starch, 

 in some cases to the extent of fifty per cent.; these mi.\tures are coloured 

 with turmeric generally, and we understand in some cases chrome 

 yellow, but we have not met with an instance : the necessary pungency 

 is produced by the addition of cayenne pepper. 



The microscope is sufficient to detect all these adulterations — wheat 

 flour by the appearance of its starch grains ; tumeric, by the most 

 characteristic form of its colouring matter (but the character of this is 

 still further den:!onstrated by the addition, under the microscope, of 

 a drop of liiq. Potassse, which has the effect of turning the particles of 

 turmeric hroicn ; but if the colouring matter be chrome yellow they 

 become much paler, or no change whatever takes place). The admix- 

 ture of wheat flour and turmeric with mustard flour has becoine so 

 general that long usage has rendered the sophisticated article more 

 popular than the genuine, for though this would be vastly more pungent. 



