On the Chemistry of Silesian Sugar-Beets. 
355 
moisture which they throw off cannot freely escape, and in con- 
sequence they are apt to heat and to suffer changes, which 
diminish the amount of crystal lizable sugar which they contain. 
Composition of Sugar- Beets. — If we take a beet-root and cut it 
across, we shall see that it is composed of concentric zones or 
layers, differing in colour, more or less, according to the variety. 
The exterior, or skin, is composed of compact cellular tissue. 
.Next will be seen concentric zones, the number of which cor- 
responds with that of the several circles of leaves forming the 
tops, and the breadth of which depends on the stage of develop- 
ment of the leaves. The oldest and most external leaves are in 
direct communication with the oldest and most central layers or 
zones, composed of cellular and vascular tissue, whilst the 
youngest and most central leaves communicate with the most 
recent external concentric zones of the root, and provide them 
with nourishment. 
If the leaves of a beet-root are very large and luxuriant, the 
concentric rings of the root with which they communicate will 
also be found very large, the tissue of their rings spongy, and 
the cells large and filled with sap that is, comparatively speaking, 
watery and poor in sugar. 
On the other hand, the less luxuriant and smaller tops of well 
grown moderate sized beets will be found to correspond with 
concentric layers of cells of smaller dimensions, to be filled with 
a denser sap, richer in sugar than we find it in roots with large 
tops. 
The best roots for the manufacture of sugar are those in which 
the size of these concentric layers of cells does not exceed 4^ to ^ 
of an inch. As a rule such roots do not weigh more than 2 lbs. 
each ; their flesh is more firm and less transparent than that of 
big heavy roots, which exhibit on a cross section large concentric 
zones or layers of cells, filled with a liquid much poorer in sugar. 
The walls of the cells are composed of cellulose, and upon 
this is deposited a gelatinous matter, called pectose, which 
occurs in all bulbous roots, and in fruits from which jelly can 
be obtained. Besides cellulose and pectose, constituting the 
bulk of the expressed pulp of beet-root, the latter contains small 
quantities of soluble albuminous compounds and insoluble mineral 
matters, chiefly composed of insoluble salts of lime. The liquid 
contents of the cells, or beet-root juice, contain in addition to 
sugar, their chief constituent, an appreciable amount of vegetable 
casein and analogous nitrogenous compounds, a little green 
colouring matter, oil, a peculiar acrid-tasting substance which 
has not as yet been satisfactorily isolated, citric, and probably 
other organic acids, and a number of saline compounds which 
constitute the soluble portion of the ash of beet-root. 
