January 11, 1873.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
OxO 
the well developed vessels. These vessels may he 
regarded as types of one class of vessels, but must 
not be more fully referred to here. 
Cinnamomi Cortex. —The chief adulteration of 
cinnamon either in the form of powder or otherwise 
is by admixture of cassia with, in the case of powdered 
cinnamon, the addition of some form of starch. It 
is not difficult, as every one who deals with the two 
articles knows, to distinguish between “whole” 
cassia and cinnamon, but the case is very much 
otherwise when we have to distinguish between un¬ 
adulterated cinnamon powder and either powdered 
cassia or an admixture. It is perhaps impossible 
to detect a small amount of admixture of cassia with 
cinnamon in the powdered state, but it is perfectly 
easy to detect any considerable admixture or to dis¬ 
tinguish between the two powders. But to be able 
to do so requires prolonged and careful study of the 
special features of each of these barks. Their pre¬ 
paration for microscopical examination is more easy 
than is the case with most barks. A short macera¬ 
tion in warm water will render either of them suffi¬ 
ciently soft to permit very thin sections to be cut 
both transversely and longitudinally, the latter in a 
direction perpendicular to the surface. The only 
precaution to be taken is to take care that the piece 
of bark, especially if cinnamon, is well wedged in the 
section cutter with pieces of good cork. The best 
plan being to select a fine textured cork, the size of 
the tube of the section instrument, to halve it, take a 
thin slice from each half, and then place the piece of 
cinnamon between the halves, and put the whole into 
the section instrument. Very fine and perfect sec¬ 
tions may thus be cut with great ease, and will show 
the whole of the tissues without solution of continuity, 
such as will result from careless cutting. The razor 
should be well wetted and the sections floated into 
water, whence they may be at once mounted in fluid 
or glycerine jelly, or removed to alcohol, boiled 
therein for a second, transferred to oil of anise and 
heated therein for half a minute, and finally mounted 
in dammar or balsam. This last plan is particularly 
applicable to sections of cassia, stained with magenta 
and intended to be viewed by polarized light, but in 
this last event the sections should be cut either from 
a piece of dry bark or from a piece that has been 
soaked in cold water onl} r , this being necessitated by 
the ease with which cinnamon and cassia starch 
undergoes transformation. 
It will perhaps be more useful if I describe the 
structure of cinnamon in comparison with that of 
cassia, omitting all reference to such minor points 
as they have quite in common. Its general structure 
is characteristic enough. Beginning at the outside, 
we have first a layer of flattened cork cells, some¬ 
what brown in colour, and not otherwise of special 
interest. In cassia these are slightly larger than in 
cinnamon, but are otherwise similar. There are 
sometimes two or three layers of cells of this 
class present in both cinnamon and cassia; more 
• frequently in the case of the latter. Beneath these, 
in the case of cinnamon as a tolerably complete and 
continuous la} r er, and less complete and continuous 
in the case of cassia, are, what Hassall calls, 
“stellate cells,” that is, cells whose interiors are 
almost wholly filled up with deposits of secondary 
matter (sclerogen); very distinct pores traversing 
the deposits. These cells have, in cinnamon, seldom 
any contents, and their central cavity is but small. 
In cassia the cavity is larger, and sometimes (“ fre¬ 
quently’’—Hassall) contains starch. They are 
larger, and in proportion to the other tissues, less 
numerous in cassia than in cinnamon, and are best 
seen in longitudinal sections, and can be easily iso¬ 
lated if desired. These cells, carefully mounted in 
thick balsam without preliminary soaking in essen¬ 
tial oils, show the successive deposition of secondary 
matter and the arrangement of then- pores remark¬ 
ably well, and on this account are deserving the at¬ 
tention of beginners in structural botany. Unless 
care be taken they may be confused with a very 
different structure, especially if studied in cross sec¬ 
tions of the bark, the much thickened liber cells, 
very numerous in cassia, and almost wholly filled 
with sclerogenous matter. The absence of pores in 
cross sections of these liber cells, of course, at once 
distinguishes them from the “stellate cells,” and dis¬ 
section of the whole tissues confirms the diagnosis. 
If a section be stained with magenta, and carefully 
boiled in alcohol for a few minutes afterwards, these 
several features are easily demonstrated, and such a 
section is furthermore a very pretty object. 
The parenchymatous tissues of cassia and cin¬ 
namon are very dissimilar. One very prominent 
feature is the presence of great quantities of large 
starch granules, eminently doubly refractive, and 
giving a black cross with polarized light in the case 
of cassia, and of very much smaller quantities of 
smaller-sized starch corpuscles in the case of cinna¬ 
mon; excepting in size and number the starches are 
very similar. The cells of this tissue are larger in 
cassia, and much more thickened than in cinnamon. 
These differences are best seen in stained sections. 
Small quantities only of starch should be present 
in good and pure ground cinnamon. The presence 
of foreign starches is, of course, a matter of easy 
detection, but is not, so far as my experience goes, 
of common occurrence. A proportion of the oil may 
sometimes be extracted before grinding the bark ; 
but the microscope would only enable us to guess at 
this by the transformation of the starch granules 
under the action of heat and water, and by the 
absence of or alteration of certain small masses of 
brownish-yellow colouring matter, common to 
both cassia and cinnamon. As before said, careful 
study of the minute structure of the two barks is 
needful to enable us to tell “ which is which;” but, 
granting this careful study, the difficulties in the 
way of so doing are not very serious. 
THE HATE AT WHICH AMMONIA DISTILS 
OVER FROM WEAK SOLUTIONS. 
RY J. ALFRED WANKLYN. 
In the first number of the new series of the 
Mechanics' Magazine I am publishing a mathema¬ 
tical theory of “ Fractional Distillation.” Some of 
the material, however, which is contained in the 
paper has other bearings, and, in particular, some 
experiments on the distillation of ammonia appear 
to me to be of interest to all chemists who are work¬ 
ing the ammonia process of water-analysis. 
The following experiments on dilute solutions 
of ammonia will possibly afford acceptable data for 
laboratory use:— 
Into a litre of water 1000 milligrams of ammonia 
were placed, and the liquid distilled. The first 50 c. c. 
