934 
riment in the succeeding winter, I 
found it had not succeeded accord- 
ing to my hopes, for a portion of 
the alburnum, in almost every in- 
Stance was lifeless, aud almost dry, 
toa considerable distance below the 
space from which the bark had been 
removed. Ia one instance the whole 
of it was, however, perfectly alive ; 
and in this I found the specific gra- 
vity of the wood, above the decor- 
ticated space, to be 1114, and be- 
low it 1111; and the wood of the 
unmutilated pole, at the same dis- 
tance from the ground, to be 1312, 
each being weighed as soon as it was 
detached from the root. 
Had the true sap in this instance 
wholly stagnated above the decorti- 
cated space, the specific gravity of 
the wood there ought to have been, 
according to the result of former 
experiments, comparatively much 
greater; but I do not wish to draw 
any conclusion from a single expe- 
riment; and, indeed, I.see very 
considerable difficulty in obtaining 
aby very Satisfactory, or decisive 
facts, from any experiments on 
plants, in this case, in which the 
same roots and stems collect and 
convey the sap during the spring 
and summer, and retain, within 
themselves, that which is, during 
the autumn and winter, reserved to 
form new organs of assimilation in 
the succeeding spring. In the tube- 
rous-rooted plants, the roots and 
stems which collect and convey the 
sap in one season, and those in which 
it is deposited, and reserved for the 
succeeding season, are perfectly dis- 
tinct organs; and from ene of these, 
the potatoe, I obtained more inte- 
resting and decisive results. 
My principal object was to prove 
that a fluid descends from the leaves 
and stem to form the tuberous roots 
ANNUAL BEGISTER; 
1806. 
of this plant;and that this fluid will 
“in part escape down the alburnous 
substance of the stem, when the con- 
tinuity of the cortical, vessels is 
interrupted: but I had also another 
object in view. 
Every gardener knows, that early 
varieties of the potatoe never afford 
either blossoms or seeds, and I at- 
tributed this peculiarity te.privation 
of nutriment, owing to the tubers 
being formed preternaturally early, 
and thence drawing off that portion 
of the true sap, which, in the ordi- 
hary course of nature, is employed 
in the formation and nutrition of 
blossoms and seeds. : 
I therefore planted, in the last 
spring, Some cuttings of a very early 
variety of the potatoe, which had 
never been known to blossom, in gar- 
den pots, having heaped the mould as 
high as I could above the level of the 
pot, and planted the portion of the 
root nearly at the top of it. When 
the plants had grown a, few inches 
high, they were secured to strong 
sticks, which had been fixed erect in 
the pots for that purpose, and the 
mould was then washed away from the 
base of their stems by a strong current 
of water. Each plant was now sus- 
pended in air, and had no commus 
nication with the soil in the pots, 
except by its fibrous roots, and as 
these are perfectly distinct organs 
from the runners which generate and 
feed the tuberous roots, 1 could 
readily prevent the formation of 
them. Efforts were soon made by 
every plant, to generate runners and 
tuberous roots; but these were de- 
stroyed as soon as they became per- 
ceptible. An increased luxuriance 
of growth now became visible in 
every plant, numerous blossoms 
were emitted, and every blossom af- 
forded fruit. 
Conceiving 
