784 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[April 5, 1873. 
potassium, the bitter taste in the black mustard can 
be entirely removed, making it more agreeable for 
table use. 
I think it would be an advantage if some certain 
proportions of the two seeds were given in our 
materia medica, so as to define absolutely what is to 
be understood as the official mustard. 
Having considered mustard from a pharmaceutical 
point of view, I will now add a few remarks on the 
mustards of commerce, neither of which can be called 
the mustard of the Pharmacopoeia. 
I have examined a large number of commercial 
mustards, and find that they are all more or less 
mixed compounds. I am indebted to Mr. Martindale 
for several samples obtained in various parts of the 
metropolis, in one of which there is from 30-50 per 
cent, of a mixture of wheat and pea flour, the colour 
of the latter admirably adapting it for this purpose. 
I do not know a better or more interesting subject 
than mustard for the “’prentice hand” of the student 
using his microscope for the advancement of phar¬ 
macy. Let him take a black mustard seed ; soak it 
an hour in cold water, then boil it in a dilute solution 
of caustic potash (about 1 pt. of Liq. potassm to 20 
of water). He will then be able to separate the 
three coats of which the integument is composed, 
and study them under his microscope. I have here 
several slides of these three coats which may be 
examined presently, and from which the accompany¬ 
ing woodcut has been made. The middle coat is the 
characteristic coat of the black mustard seed, and 
contains the colouring matter ; an intimate acquaint¬ 
ance with these coats will teach him what is black 
mustard when he meets with it under the microscope. 
In the top right-hand corner is a drawing of the cha¬ 
racteristic cell of the white mustard. Then let him 
take a sample of commercial mustard, place a little 
of it with a drop of water on his slide, and cover it 
with a glass, and with a power of 250 to 300 linear 
he will see starch grains. If his eye has not been 
accustomed to recognize starch-grains under the- mi¬ 
croscope let him touch the contents of the slide with 
a drop of a solution of six drops of tincture ©f iodine 
to an ounce of water, when the granule of starch will 
assume a faint violet colour. And I would hero 
caution him against a mistake he may be likely to 
commit. If he mixes the mustard with water in a 
watch-glass, adding a small quantity of this very 
dilute solution of iodine, the development of the 
volatile oil will decolorize any starch that may be 
present before it is examined. 
I would recommend to the careful consideration of 
the student some remarks of Mr. Stoddart on this 
subject in “Bristol Pharmacology” (Ph. Journal, 
Vol. I., 3rd Series, p. 661). 
I am indebted to Mr. Rochfort Connor, of Somerset 
House, for these very beautiful and accurate draw¬ 
ings which are now exhibited, showing the several 
coats of the black and white mustard seed, and I am 
happy to see him amongst us this evening. 
It is not my intention on this occasion to consider 
the dietetic uses of mustard; but I would express- 
this opinion, that there is no necessity for the ad¬ 
mixture of any foreign ingredient, such as wheat- 
flour, turmeric, or capsicum. 
Black mustard-flour mixed with one-sixth of its 
weight of white, will make a condiment acceptable 
for table use, and at the same time suitable for the 
Cataplasma sinapis. 
The consideration of the Charta sinapis of the 
future would occupy too much of our time this 
evening ; but I hope on a future occasion to bring 
this subject specially under your notice. 
THEJ1EXTINCTI0N OF MERCURY Ilf 
FATTY BODIES.* 
BY M. MAGNES-LAHENS. 
Many fatty bodies have been successively vaunted 
as having a special action upon the extinction of 
mercury, and this action has been often attributed to 
their chemical composition; but the author is of 
opinion that the consistence of these fats exercises 
a much greater influence upon the extinction of the 
mercury than their composition. He has, in fact, 
found,— 
(1.) That fats naturally liquid, employed in small 
quantity, reduce the mercury to a homogeneous and 
permanent paste with considerable and nearly equal 
rapidity; the advantage, however, being in favour of 
those liquid fats which have the most fluidity. 
(2.) That fats naturally solid, employed in the 
same proportions, extinguish the mercury with a 
difficulty and slowness proportional to their hard¬ 
ness ; but that when liquefied completely by heat, 
they accomplish the extinction nearly as quickly as 
the naturally liquid fats. This extinction, however, 
is not permanent, and the mercury reappears in large 
drops, as, in cooling, the mass hardens and cracks in 
a thousand places. 
M. Lahens therefore concludes from these experi¬ 
ments that the extinction of the mercury is due to a 
slight layer of fat which envelopes the imperceptible 
globules of mercury, keeping them separated one 
from another, and that the extinction continues or 
* Abstracted from paper in the Journal de Pharmacie. 
et de Chimie [4], vol. xvii. p. 220. 
