THE DETECTION OF ADULTERATION IN FOOD. 33 
The paper was illustrated by a number of drawings and mounted 
slides of many of the species referred to, as well as by a selection 
of excellent slides prepared by Mr. William West, of Bradford, and 
kindly lent for the occasion by Mr. Thomas Rogers. 
fil DETECTION, OF ADULERRATION 
IN FOOD. 
By C. M. Vorce, F.R.M.S. 
MUSTARD. 
HIS condiment, of so universal use, is probably never obtained 
strictly pure. The commercial article is the flour of the seeds 
of black mustard and white mustard mixed in a proportion that 
varies with the fancy or honesty of each manufacturer ; the black 
mustard seeds furnishing the best mustard flour. To the mustard 
flour is added a large proportion of wheat flour, which serves to 
absorb and retain the abundant oil of the crushed mustard seeds, 
and it thus ranks as commercially pure. A celebrated English 
manufacturer of mustard uses 56 lbs. of wheat-flour to r12 lbs. of 
mustard-flour made from two parts of black to one part of white 
seed. This mixture is accepted as a very superior article of “pure 
ground mustard.” In cheaper grades of mustard the proportion 
of wheat-flour is increased, the sifting out of the mustard seed husks 
is less perfect, rye-flour and other cheaper flours and corn meal 
are used, and various adulterants are added, of which one of 
the most common is turmeric, as it also serves to darken the yellow 
colour of the mixture when much starchy flour is used. 
The mustard seed itself is also subject to adulteration, but not 
extensively, cheaper and harmless seeds being mixed with it, 
clove seed being the most common. The appearance of the mustard 
seed under the microscope is beautiful indeed, the surface is 
covered with a network of raised ridges enclosing shallow concave 
pits of rudely hexagonal shape, smaller and more irregular as they 
converge toward the micropyle of the seed, and containing a 
shrunken membrane-like layer of glistening white substance lining 
the sunken cavity, and in some places looking like a flat scale-like 
crystal lying in the pit, fig. 1. The shell or husk of a dry seed 
examined in turpentine or water, exhibits a rudely hexagonal 
areolation, and is apparently thickly punctured with small holes, 
and of a somewhat translucent red colour, like coloured horn. 
fig. 2, a. The seed-shell is lined inside and out by a thin, close, 
_ cellular membrane, the outer one with very much larger cells than 
