40 DR. A. D. WALLER ON THE 
$17. Clearly land-plants are more interesting than sea-plants. 
But the contrast between the two kinds, whatever its meaning 
may be, is a fact of primary importance. I want to confirm it, 
or the reverse, by every means in my power. So I offer at the 
next meeting of my family to give two prizes—one for any 
blazing sea-plant, the other for any non-blazing land-plant. I 
make the proviso as to the latter that it must be a plant capable 
of conducting an electrical current, not a non-conducting dry 
leaf or bit of wood. I also stipulate, as conditions of the prizes, 
that the winning land-plant shall give less than 0°001 volt, the 
winning sea-plant more than 0:010 volt. 
Many things are brought to the galvanometer in a short space 
of time, from the garden and from the sea-shore. Nothing from 
the garden fails to blaze ; nothing from the sea-shore gives any- 
thing like a blaze. "True, a holly-leaf from the garden gave no 
clear blaze; but its electrical resistance was so great that 
current sufficiently strong to excite could not traverse it. 
And, on the other hand, a leaf from among the seaweed which 
did give a blaze was pronounced to be an intruder from a neigh- 
bouring stream. 
The competitors abandoned their quest as hopeless, being even 
more convinced than I am that land-plants blaze, while sea-plants 
do not blaze. 1 am indeed satisfied that sea-plants do not blaze 
anything like land-plants ; but I am not sure—indeed, I think it 
quite unlikely—that no sea-plants give any blaze at all *. 
$18. An Ivy Petiole versus a Geranium Petiole—All land- 
plants are not equally vigorous as regards their electromotive 
effects ; some are more vigorous than others. I found, a year 
or two ago, that seeds lose power in this respect by mere lapse 
of time. 
An ivy-leaf petiole as compared with a geranium-leaf petiole, 
under physical conditions as nearly as possible identical, affords 
a convenient illustration of the general principle that amount of 
blaze bears some general relation to degree of vitality or vivacity. 
* Ultimately a long narrow seaweed, called “ boot-laces" by the fishermen, 
Chorda Filum by its museum name, was brought in, and gave typical 
homodrome effects in both directions, amounting to as much as 0:02 volt. The 
peculiarity is possibly due to the transverse septa subdividing the length of 
weed. Another jointed seaweed coralline was subsequently found, giving about 
OOl volt. 
