1810.] , 
ted by the leaf-stalk derive their exist- 
ence. Ifa portion of the bark of a vine 
be taken off in a circle, extending round 
its stem, so as to intercept entirely the 
passage of any fluid through the bark, 
and any body which contains much mois- 
ture be applied, numerous roots will 
soon be emitted into it immediately 
above the decorticated space, but never 
immediately beneath it; and when the 
alburnum in the decorticated spaces has 
become lifeless to a considerable depth, 
buds are usually protruded beneath, but 
-never immediately above it, apparently 
owing to the obstruction of the ascend- 
Ing sap. The roots which are emitted 
in the preceding case, do not appear in 
any degree to differ from those which 
descend-from the radicles of generating 
seeds, and both apparently derive their 
matter from the fluid which descends 
through the cortical vessels. 
Mr. K. anticipated the result of this 
and other experiments mentioned by 
him ; ‘ not,” 
that roots can be changed into bads, or 
buds into roots, but J had before proved 
that the organization of the alburnum is 
better calculated to carry the sap it con- 
tains from the root upwards, than in any 
other direction; aud I.concluded that 
the sap, when arrived at the top of the 
cutting through the alburnum, would be 
there employed i in generating buds, and 
that these buds would be protruded 
where the bark was young and thin, and 
consequently afforded little resistance : 
I had also proved thai bark to be better 
éalculated to carry the sap towards the 
roots than in the opposite direction; 
and I thence inferred, that as soon as 
any buds, emitted by cuttings, afforded 
leaves, the sap would be conveyed from 
these to the lower extremity of the cut- 
tings by the cortical vessels, and be there 
einployed in the formation of roots.” 
Both the alburnum and bark of trees 
contain their true sap; and as this, like 
the animal blood, is probably filled with 
particles which are endued with life, 
Mr. K. conjectures that the same fluid, 
by acquiring different motions, may ge- 
nerate different organs, than that two 
distinct fluids should be necessary to 
form the root, and the bud and leaf. 
When alburnum is formed in the root, 
that organ possesses, in common with 
the stem and branches, the power of pro- 
ducing buds, and of emitting fibrous 
roots; and when it is detached “from the 
tree, the buds always spring near its 
upper end, and the roots near the op 
Proceedings of Learned Societies. 
says he, “that L supposed - 
469 
posite extremity. The alburnum of the. 
root is also similar to that of other parts 
of the tree, except that it is more porous, 
probably owing to the presence of abun- 
dant moisture during the period in which 
it is deposited. Perhaps the same cause 
may retain the wood of the root per- 
manently in the state of alburnum; for 
if the mould be taken away, so that the 
parts of the larger roots which adjoin the 
trunk be exposed to the air, such parts 
are subsequently found to contain much 
heart wood. 
In opposition to the opinion that 
fibrous, like bulbous roots, of all plants, 
are only of annual duration, it 1s observed 
that, with regard to the latter, nature 
has provided a distinct reservoir for the 
sap, which is to form the first leaves and 
fibrous roots of the succeeding season ; 
but the organization of trees is different, 
and the alburnum and bark of the roots 
and stems of these, are the reservoirs of 
their sap during winter. When how- 
ever the fibrous roots of trees are 
crowded together in a garden-pot, they 
are often found lifeless in the succeeding 
spring; but this mortality does not occur 
in the roots of trees when growing under 
favourable circumstances 10 their natural 
situation. 
In a future communication, the author 
means to point out the causes which di- 
rect the roots of plants in search of pro- 
per nutriment, and which occasion the 
root of the same p.ant to assume differs 
ent forms under different circumstances, 
Mr. Jonn George Curtipren laid be= 
fore the society an account of some ex- 
periments on the most advantageous mee 
thod of constructing a Voltaic apparatus, 
His battery consisted of upwards of 
ninety-two thousand square inches in 
surface, each plate being four feet by 
two; and it was charged ‘with a mixture 
of three parts of fuming nitrous, and one 
part of sulphuric acid, diluted with thirty 
varts of water. With this battery he 
fused completely eighteen inches of 
platina wire, sth of an inch in diameter, 
_in twenty aides and ten inches of 
iron wire, x5¢h of aninch tnick: charcoal 
was burnt, giving out an intense brilli- 
ancy. But on imperfect conductors it 
had not the slightest effect; and on the 
human body it was hardly perceptible : 
and it had scarcely any effect on the gold 
leaves of an electrometer. But witha 
second battery, consisting of two hundred 
pair of plates each, about two inches 
square, placed 1 1D half-pint pots of come 
mon queen ‘s-ware, and rendered active 
by 
