36 THE MICROSCOPICAL NEWS. 
various sizes and shapes, opaque in the thicker parts, and with the 
cells filled with a minute granular substance (fig. 7). Some scales 
and cells of the outer membrane of the shell (fig. 11), are seen, 
some separate cells of the mustard seed (fig. 6), and a very few 
minute fragments of the shell. 
The mustard seed is, by some, said to contain no starch at all; 
by others to contain “little or none,” and by others to contain 
“very little,” “but a trace,” etc. I have not been able to satisfy 
myself of the presence of starch in the mustard seed, but the cells 
of the cotyledon are filled with minute granular matter (figs. 4, 5, 6, 7), 
which almost entirely dissolves in potash with heat, leaving the cells 
empty with their cell-walls thickened (fig, 8), and in the water in 
which a dry seed is crushed, can be seen numerous minute drops 
of oil, similar to what was figured in the article on Capsicum, and 
many very minute granules (fig. 9), which are solid and clear, and . 
float in the water ; they dissolve in potash but do not polarize, nor 
do they seem to stain by dilute iodine, and they do not swell 
appreciably on being heated in water. I could discover no trace 
of a hilum, but am inclined to believe from analogy that these 
minute granules are, in fact, starch. 
In examining samples of ground mustard to detect adulteration, 
first drop a little into alcohol and see if it instantly gives the yellow 
color indicative of turmeric ; if so, place a little in water under the 
microscope and determine as nearly as possible the percentage of 
turmeric present, also note the proportion of wheat-flour, and 
whether any other starchy matter is present. The addition of 
dilute iodine will mark the starches, leaving the fragments of 
mustard uncolored, and thus facilitate the determination:; finally 
add strong potash solution and note what proportion is left after all 
the starch is dissolved. A fresh sample should also be examined 
in turpentine, and another should be treated with nitric acid, by 
which means any fragments of other seeds than mustard will be 
detected, and lastly, still another sample should be treated with 
potash and heat, and examined for fragments of seed-husks other 
than mustard husks. Acid after potash will often soften woody 
fragments that resisted the potash, and enable their structure to be 
detected. 
1. Dry seed, opaque by %-in. objective. 
2. Shell of dry seed in turpentine ; a, substance of the shell; 4, 
ridges of outer surface ; ¢- membrane of outer surface ; d, 
inner membrane, + 236. 
Section of dry seed shell+ 215. 
Section of dry cotyledon + 47. 
Section of same in water + 215. 
Separated cells of seed ; a, of cotyleden ; 4, of radicle, + 236. 
. Fragments of mustard flour+ 215. 
SOT EY 
