98 DR. A. D. WALLER ON THE 
$10. From a second visit to the garden and to the sea-shore 
respectively, I bring back two bundles—one of land-plants, the 
other of sea-plants. Everything from the garden gives me 
blaze-currents; nothing from the sea-shore does so. I am 
entitled to say that land-plants blaze, and that sea-plants do 
not blaze. I do not at this stage commit myself to any 
quantifying prefix to the subjects of these two propositions ; 
more extensive trials will be required before we shall venture 
to say whether only “some,” or ** most," or “all”? land- and 
sea-plants do or do not blaze. 
$11. So we set ourselves the task of finding, on the one 
hand, a land-plant that does not blaze, and, on the other, a 
sea-plant that does blaze. We hardly expect to find a hard- 
and-fast “yes” or “no” in every case we try, but rather a 
differenee of degree, perhaps; so we shall take note of the 
voltage uf the blaze-currents, by comparing their galvanometric 
effects with the effect through the same circuit of a known 
standard voltage. Of course this will not mean that we have 
arrived at any true electromotive value of the blaze-current, 
but it will be better than nothing. 
§ 12. I think of water-plants, and ferns, and fungi as possibly 
non-blazing land-plants. So I fetch some watercress, and leaves 
of hart's-tongue fern, and a fungus from a tree-stump in the 
garden. 
$ 13. I begin with the fungus :— 
0'001 volt gives a deflection............ = 25mm. 
Exc, by Br+10000 gives homodrome blaze ...... = +250 
»  Br—10000 ,, nothing at all. 
»  2Br4-10000 ,, a smaller blaze 
»  Br—10000 ,, nothing at all. 
The fungus evidently gives a blaze-current; but beyond this 
bare fact there are already several points of detail that must 
arouse reflection and provoke further study. 
The blaze-current is only in one direction, from B to A, 
“ positive," and aroused only by current in that same positive 
direction. On looking to see how the fungus is orientated 
between the eleetrodes, I find that the dorsal surface is on B 
and the ventral surface is against A; so that the blaze just 
witnessed has been from dorsal to ventral surface. It has been 
aroused by a break induction-shock in the same direction, 
having therefore the anode at the dorsal surface; it has not 
LE 
ennt =+ 60 I 
