On the Cliemistry of Silesian Sugar-Beets. 353 
tiinmonia on such land does harm, inasmuch as it both diminishes 
the percentage of sugar in the beets, and prevents the manufac- 
turer obtaining, in a crystallized form, as large an amount of sugar 
as he can produce from beets containing the same percentage of 
sugar, but grown without the use of nitrogenous manure. 
Common salt, so largely applied to mangolds in this country, 
and nitrate of soda retard the ripening process, and in con- 
sequence act injuriously on sugar-beets. On the other hand, 
pliosphatic manures favour early maturity. Superphosphate of 
lime may therefore be applied to the land with excellent effect at 
the time when the seed is drilled in. Bone-dust also does no 
harm, but good, to beets. On light soils, in which potash is gene- 
rally deficient, a mixture of superphosphate and sulphate of 
potash having been found most serviceable to beets in many 
cases, can be thoroughly recommended, not only upon light sandy 
soils but upon all soils in a comparatively poor agricultural 
condition. 
Maturity of Roots. — Beet-roots generally get ripe in about five 
months. When sown in the middle of April they will thus be ripe 
in an average season about the middle of September. However, 
much depends on the season and the character of the land in 
bringing the crop to maturity, and therefore the length of time 
during which the crop should be left in the ground cannot be 
expressed in general terms. The best time for taking it up is 
that when the roots are nearly ripe. This stage of development 
is recognised by most of the leaves turning yellow and flabby. 
As long as the tops are still quite green and succulent the roots 
■will be found in a growing state, and as long as they continue to 
grow, sugar continues to be stored up in them. Should the 
weather be cold and no rain fall in autumn, the crop may be 
left in the soil without injury a week or fortnight after the roots 
are quite ripe. But should the autumn be mild and wet every 
chance is given to the roots to make a second growth, which 
should be avoided by all means, inasmuch as the young leaves 
m that case are produced in a great measure at the expense of 
stored up sugar in the roots. Nothing does so much injury to 
the beets as a second growth of tops after the roots have 
become ripe, and hence the safest plan is to take them up as 
soon as possible after the crop has arrived at maturity. Particu- 
lar attention, therefore, should be paid by the beet-root grower 
to watch the ripening process, and he will find it useful, during 
the latter stages of growth, to test from time to time the roots for 
sugar. This may be done with sufficient accuracy for practical 
purposes, and with great ease, by grating a root or two, and 
squeezing out the juice by pressing the pulp through calico, and 
testing the specific gravity of the juice by means of a specific 
