Marcle 16, 1882] 
NATURE 
461 
village, a church, anda pastor. One winter night when a fearful 
storm was threatened, three Finns (7.2. Lapps) entered the valley 
ana begged shelter in vain of the inhabitants, At last they 
asked the priest, and he too refused. Then the wrath of the 
heathen wizards was raised, and they solemnly cursed the valley 
and doomed it to destruction by the crawling power of the ice, 
until the glacier reached the lake below. The Lapps were seen 
no more, but on their disappearing the snow began to fall. The 
winter was awful. The glacier approached by awful steps, and 
‘by degrees engulfed the cursed valley and farms. Nor is the 
curse yet exhausted, for the glacier creeps down the valley each 
year, and has yet a mile to go before it reaches its destination in 
the lake above Odde. I am no judge of folk-lore, but this 
weird tale seemed to me a genuine piece of it, and not invented 
for the occasion, as Olsen gave it half jokingly as the tradition of 
the district. The farmer who owns the remnant of the doomed 
valley, wanted then to sell it, as he saw his acres swallowed up 
each year, but noone will buy. If this tale be genuine, it points 
to a prolonged advance of the Folgefond, which has led to the 
tale of the Lapps’ curse. Those interested in ice-action will see 
a fine example of the ‘‘ Tyssenstrengene,” or polished stone fells 
of Norway, between Odde and the splendid Skjegadals (or 
Ringedal’s) Fos. The rocks are so polished by the ancient ice 
that a path is made over them by putting rough fir trees down to 
give a foothold. The ice-polishing on the Grimsel Pass in 
Switzerland, is a mere nothing to these ‘‘ Tyssenstrengene.” 
J. INNEs ROGERS 
Intelligence in Birds 
Our English jackdaws are not behind Miss Bird’s Japanese 
crows in at any rate one of the instances of intelligence told by 
her. Many years ago it was a frequent amusement of ours to 
watch the encounters between a tame jackdaw and the stable 
cat. The cat’s dinner used to be put down outside the stable- 
door, and, warned by experience, she hastened to dispose of as 
much as possible before the arrival of the jackdaw. He seldom 
went directly to the meat in the plate, but attacked the enemy in 
the rear, settling himself with both feet on her outstretched tail 
to steady it, and then administering pickaxe blows on it with his 
beak. Of course it was impossible to stand this, and with a 
forcible exclamation the cat used to spring away, and Jack took 
possession of the plate, until our sense of justice obliged us to 
recall and defend the rightful owner. E. HUBBARD 
March 6 
Auroral Display 
I SEE by your number of NaTuRg, vol. xxv. p. 386, that an 
auroral display was witnessed in England on February 20, be- 
tween 7 and 8 p.m, A very magnificent one was seen in the 
Hardanger-fjord on the same evening at the same hour, by a 
friend of mine, and the Captain of the ss. Avlvefonden says he 
has never seen a finer, Could it have been the same aurora ? 
W. E. Kocu 
Lysefjord near Stavanger, Norway, March 9 
ON THE CHEMISTRY OF THE PLANTE AND 
FAURE ACCUMULATORS 
PART Il.—The Charging of the Cell 
iN NATURE (vol. xxv. p. 221) we directed attention prin- 
cipally to the local action that takes place on the 
negative plate of a Planté or Faure battery. We pointed 
out the close analogy between zinc coated with spongy 
copper, and lead coated with spongy peroxide, in their 
action on water or dilute sulphuric acid ; and we showed 
the importance of the lead sulphate produced in modera- 
ting this action. We now propose to treat of the chemical 
changes involved in the preparation of the cells. 
The procedure of Planté in forming his battery is at 
first sight extremely simple. He takes two coils of lead, 
separated from one another, and immersed in dilute sul- 
phuric acid ; a current is sent through the liquid from one 
lead plate to the other, and the final result is, that the one 
becomes covered with a coating of lead peroxide, while 
hydrogen is given off against the other plate. On the 
view that the sulphuric acid merely serves to diminish | 
the resistance, and so facilitate the electrolysis .of water, 
the ready explanation would be given that the two ele- 
ments of the water are simply separated at the two poles, 
But it seems more in accordance with the facts of elec- 
trolysis, to suppose that the sulphuric acid, H,SQ,, is 
itself the electrolyte, and that the oxygen results from a 
secondary chemical reaction. As a matter of fact, if water 
be employed, no peroxide is formed, but only the hydrated 
protoxide, even though a current from twenty-four Grove’s 
cells be made use of. The addition of a single drop of 
sulphuric acid to the water is enough to cause the imme- 
diate production of the puce-coloured oxide. 
If we take two plates of lead in dilute sulphuric acid, 
and pass the current from only one Grove’s cell, a film of 
white sulphate, instead of peroxide, makes its appearance 
on the positive pole, and the action practically ceases 
very soon. If, however, the current be increased in 
strength, the sulphate disappears, and peroxide is found 
in its place. In Planté’s procedure, spongy lead, and lead 
peroxide are indeed found on the respective plates. But, 
in consequence of the local action which takes place 
during the periods of repose, lead sulphate will be pro- 
duced from the peroxide, and afterwards, in the course of 
the “formation,” this must be reduced to metallic lead 
by the hydrogen. 
It may seem at first sight improbable that an almost 
insoluble salt of the character of lead-sulphate should be 
decomposed under these circumstances. To test this fact 
by direct experiment, we covered two platinum plates 
with lead-sulphate, immersed them in dilute sulphuric 
acid, and sent a current through. We found not only 
that the sulphate was reduced by electrolytic hydrogen, 
but that it was peroxidised by electrolytic oxygen. The 
white sulphate was, in fact, decomposed to a large extent 
at each plate, the positive being covered with deep choco- 
ease peroxide, the negative with grey spongy 
ead. 
The reaction which takes place in charging a Planté 
battery may be viewed in two ways. The simplest may 
be thus expressed in the notation which we have employed 
in some previous papers. For convenience, the reaction 
is divided into two stages :— 
SO,H 
Phe | Soi}? | Pby = Pbx-:| PbO, 
and 2S0;+2H,0 =2H,SO,. 
But it may be that lead-sulphate is always formed in the 
first instance, and decomposed on the continuation of the 
current. 
Pbz | SO,H, | Pby = Pbr —x | SO,Pb] H, | Pby. 
then 
Pbx —x|SO,Pb | SO,H, | Pby = Pbx-—1| PbO: 
26 H, | Pby. 
and 2S0,+2H,0=2H,S0,, 
It seems not improbable that both these reactions may 
take place according to the varying density, or other 
circumstances of the current. The coating of peroxide 
interposes a great difficulty in the way of the further 
oxidation of the metallic lead. Hence Planté needs the 
successive periods of repose, to admit by local action of 
the formation of lead-sulphate, and the oxidation of the 
increasing amounts of finely-divided lead thus brought 
into the field of action. 
To obviate this waste of power and time, Faure covers 
both plates with red lead, and converts this into spongy 
peroxide and spongy lead respectively by the current. 
Now the first thing that happens, when the plates are 
immersed in the dilute sulphuric acid is a purely chemical 
action, The minium suffers decomposition according to 
the formula— 
Pb,O,+2H,SO,=PbO,+2PbS0,+2H,0. 
SO, 
SO, 
H, 
a! | Phy. 
