January 13, 1872.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
577 
or less in a straight line, without intertwining ( Scolo - 
pend Hunt , Datura , vichillca, Conium ), or they extend in a 
circle towards the edge, without touching it, and com¬ 
bine into a fine network. 
One ot the several subdivisions of leaves contains the 
aromatic leaves of the Labiates. It includes the non-per¬ 
ennial leaves of labiates, remarkable for their aromatic 
smells, owing to essential oils; these oils of various com¬ 
position are exclusively, or at least chiefly contained in 
excessively developed hair or glands, dispersed some¬ 
times on both sides of the leaf, sometimes only on the 
under side, frequently sunk into the epidermis between 
the ordinary hair of the leaves. They generally occur 
in two distinct forms, differing not only in shape and 
size, but also in structure and 
. S 
other behaviour; we 
may call them large 
and small glands. 
The small glands (c) 
form a short hair of 
one to three cells, the 
end cell of which is 
expanded in globular 
or ellipsoid shape, and 
is either single or en 
closes two adjoining 
secondary cells; the 
large cells A, B, on a 
short stalk (.v), contain 
in the perfect state in 
one primary cell eight 
secondary cells (a), 
with extremely deli¬ 
cate walls. These 
last generate the es- 
which, 
a later 
Part of a Section from a Leaf of 
Melissa officinalis, 
A. Lanre gland; (<r) secondary cells; 
( b ) space filled with essential 
oil; (s) stalk-cell; ( c) small 
gland. 
B. Large gland, seen from above. 
sential oil, 
exuding at 
period, collects above 
them, and lifts up 
the membrane of the 
primary cell in the 
shape of a globe (b ); 
this membrane is cu- 
ticular, whereas that 
of the secondary cells shows the reaction of cellulose. 
At a later period the oil appears to leave the envelope, 
at least the whole gland system is often wrapped up in 
an oil-drop, and the surrounding hair is saturated with 
oil. 
The structure of these organs is best laid bare by ex¬ 
hausting segments of leaves with alcohol and ether, and 
placing them in a drop of solution of chloride of zinc 
and iodide of potassium. The two forms of glands are 
connected by their development. In the small glands 
one surface-cell, by repeated division in a horizontal di¬ 
rection, results in the stalks containing several cells, after 
which the end cell expands globularly, and generally 
divides into two secondary cells by the formation of a 
vertical diaphragm. In the large glands horizontal 
-division produces two cells, one above the other, the 
lower of which becomes the stalk-cell, and the upper 
one, by repeated vertical partition, composes the gland 
body. Examination of young leaves clearly shows the 
different stages of development. 
We should wish to give many more instances of the 
scientific treatment of the different subjects, and our 
only difficulty consists in the selection of some article 
more valuable than the rest. We will take one on a 
well-known drug ,—rhubarb ; which, will bear out our 
assertion that the author has a singular facility in com¬ 
bining scientific observations with practical remarks. 
Until the latter part of the past century Russia was 
the only country which supplied the European market 
with rhubarb, and since 1728 exclusively via Kiachta, a 
Siberian frontier town, south-east of Lake Baikal. The 
trade in this drug was a monopoly of the Russian Go¬ 
vernment, in consequence of a treaty between Russia and 
China. All cargoes of rhubarb had to be deposited in a 
special warehouse, rhubarb-brake, and underwent a 
strict examination by experts; every piece was tested 
by boring into it or breaking it, and nothing but the 
very best quality was retained, the rest being burnt. 
The selected pieces were finally prepared by decortication, 
drying, etc., and were packed most carefully in boxes, 
which were enveloped in cloth, covered with pitch, and 
finally wrapped up in hides. Once a year, in winter, 
cargoes of 400 cwt. each were sent via Lake Baikal and 
Irkutsk to Moscow, where it was sold to the pharmacists 
to the Crown, or to other wholesale houses. 
After Canton and Macao had been opened to the 
foreigners, the rhubarb trade took a southern direction, 
and a new sort appeared in the market, under the name 
of Chinese or Canton rhubarb, as distinguished from the 
Russian or Moscow rhubarb. The opening of other 
Chinese seaports influenced the Russian trade so seri¬ 
ously, that in 1863 the brake at Kiachta was closed alto¬ 
gether, and there is now only one kind of Asian rhu¬ 
barb. 
The exterior of the drug, free from powder, shows 
white or yellowish veins or fibrous tracings, the inter¬ 
stices being filled up by a white mass with fine longi¬ 
tudinal lines of an orange-red or yellow or brownish-red 
colour (Fig. B). 
The section of a cylindrical piece, not too much decor¬ 
ticated, shows an outer 
bordering of a dark 
brown, dense, bright 
layer (cambium layer), 
about 1 mm. thick ; 
then comes a zone (ra¬ 
diate layer), about 1 cm. 
thick, of alternately 
broader white and nar¬ 
rower yellow or red 
radial stripes, the last of 
which run out into the 
cambium layer. 
Considerable hard¬ 
ness and density sets 
off this zone from the 
next, which is loose, 
pulpy and powdery, 
about half the thick¬ 
ness of the previous 
one, and recognized by 
yellow and red spots ; 
a simple circle of pe¬ 
culiar small systems of 
streaks separates the 
last zone from the cen¬ 
tral pithy mass, which 
is of a similar character. 
Larger pieces of the 
top of the root, which are well decorticated, do not show 
these regular sequels of distinct layers ; the cambium 
does not show at all, the radiate layer is generally only 
indicated, and it is mostly followed by united veins of 
different size (fig. A), which rim deep into the interior, 
or frequently also to the outside. 
According to the decortication the pieces consist either 
entirely of the woody substance, a proper pith being 
absent, or they show part of the inner bark ; this, corre¬ 
sponding to the liber, consists of extended amylaceous 
parenchyma cells and crystal fibres, and of cribriform 
tubes. 
The white primary mass belongs to the texture of the 
ligneous bundles; the yellow, red, or reddish-brown 
stripes, rays, lines and spots are pithy rays, in two or 
four rows or round cells with thin membranes ; the 
ligneous bundles consist of amylaceous parenchymatic 
elements with crystal cells, each of which encloses ox¬ 
alate of lime. 
The peculiar, and for Asiatic rhubarb characteristic, 
