and Experiments on the Keeping Qualities of Boots. 159 
noticed that the roots rich in nitrogen had a lower specific 
gravity than those poorer in this element, and richer in sugar. 
Thus root No. 11, which in a dry state contained 2.865 
per cent, of nitrogen, and only 48-023 per cent, of sugar and 
analogous compounds, had a specific gravity of only 1-003, and 
was scarcely denser than water ; whilst root No. 12, containing 
only 1-905 per cent, of nitrogen and 54 - 927 of sugary com- 
pounds, had a specific gravity of 1-039. Comparatively, much 
nitrogen in swedes, and I may add all other root-crops, in- 
variably indicates immaturity and low feeding-quality, whilst 
a moderate proportion of nitrogen and a high percentage of 
sugar in roots are certain indications of their superior feeding 
quality. The specific gravity, it will also be noticed, affords 
an excellent and simple means of judging of the relative quali- 
ties of different roots of the same kind. Advantage might be 
taken by seed-growers, more frequently than is done, of the cir- 
cumstance that good sound and nutritious roots have a higher 
specific gravity than inferior bulbs. 
A solution of common salt of the required strength, having, 
for instance, a specific gravity of 1*035 or 1-038, may be readily 
made, and by means of such solution a large number of roots 
may be tested as regards their fitness to produce good seed. 
All that requires to be done is to throw the roots in a tub 
containing a solution of salt of proper strength, and to reject 
those roots which do not sink. 
The deterioration of our root-crops, has perhaps, been caused 
as much by bad seed, raised from roots of indifferent quality, as 
by bad cultivation or excessive manuring, if not more so. On the 
Continent, where sugar-beets are grown in great perfection, the 
greatest possible care is taken in raising seed from selected 
roots of a good stock ; and undoubtedly it would well repay 
British root-growers to give a good price for turnip-seed, and 
to encourage seed-growers to raise seed from carefully selected 
bulbs more frequently than they do at present. 
Besides the character of the seed, the quality of swedes is 
much affected by the variable nature of the soil upon which 
they are grown, the kind, quality, and quantity of manure em- 
ployed, the system of cultivation, the character of the season, and 
the climate prevailing in different parts of the country. 
Over climate, and to a certain extent over the soil, the farmer 
has little or no control. On the other hand, in the selection of 
suitable manures, and in pursuing a system of cultivation best 
adapted to the peculiarities of his land, a wide margin for skill 
is left. The selection of varieties most suitable for particular 
localities or particular classes of soils, likewise affords ample 
