May 2, 1884.] 
lions of microbes in various stages of ‘ attenua- 
tion ;* and a prick from a pin-point dipped in 
any one of them might confer a horrible disease 
or future immunity from it. Yet in the midst 
of such dread possibilities the devoted experi- 
mentalist moves unharmed. 
The closing paragraph runs as follows: 
*¢ At this very moment experiments [upon the 
prevention of hydrophobia] are under full 
headway. Biting dogs and bitten dogs fill the 
laboratory. Without reckoning the hundreds 
’ of dogs which within three years have died 
mad in the laboratory, there is not a case dis- 
covered in Paris of which Pasteur is not noti- 
fied. ‘A poodle and a bull-dog | bouledoque | 
in the height of an attack; come!’ was a 
telegram sent to him recently.’’ Pasteur went, 
and took our author with him. ‘The two dogs 
were rabid ‘ aw dernier point,’ and it was only 
after some time and no small trouble that they 
were bound securely to a table. M. Pasteur 
then bent over the frothing head of the bull- 
dog, and sucked into a pipette a few drops of 
saliva. Our author remarks, in conclusion, 
that Pasteur never appeared to him so great 
as in the cellar where this took place, and while 
this ‘ téte-a-téte formidable’ was being enacted. 
> 
PLANTE’S RESEARCHES. 
Recherches sur l’électricité, de 1859 & 1879. Par 
GasTon Pianteé. Paris, La lumiere électrique, 
1883. 5+322p. 8°. 
Tue great interest taken in electric accumu- 
lators since Faure brought out his secondary 
battery, in 1881, has doubtless led to this re- 
print of Planté’s researches from the text of 
the first edition, published in 1879, and two 
supplementary papers issued a few months 
later. These researches, extending over a 
period of twenty years, are characterized by 
a neatness and originality that make them very 
attractive. ‘The writer considered himself spe- 
cially fortunate in receiving a cordial invitation 
from M. Planté, in 1881, to witness many of 
the most interesting experiments described in 
this book. A review of them recalls vividly 
the pleasure experienced in Planté’s labora- 
tory, near the celebrated ‘ Place de la Bastille.’ 
A dipléme @honneur was most worthily con- 
ferred on M. Planté at the Paris exposition of 
electricity, in recognition of his labors as the 
inventor of the secondary battery ; for, while 
polarization currents had been observed by 
other physicists previous to the beginning of 
his work in 1859, no one had pursued the in- 
vestigation with sufficient patience to make the 
SCIENCE. 
D493 
principle of any special value. It is entirely 
safe to say now, however, — in view, too, of alk 
that inventors have done within the past three 
years, — that no one can make a special study 
of secondary batteries, or succeed in making 
efficient ones, without going to these researches 
of Planté for the most essential part of his in- 
formation. As a purely experimental series, 
they must take rank with the best in the do- 
main of physics. 
It is to be regretted that M. Planté has not 
revised those portions of his researches relat- 
ing to the chemical reactions taking place dur- 
ing the charging of the cell and its discharge. 
His explanation of the formation of the perox- 
ide of lead on one plate, and of spongy lead on 
the other, has the merit of simplicity at least ; 
but, in the light of Gladstone and Tribe’s?! in- 
vestigations, it must be considered as entirely 
too simple to accord with the facts. No mention 
is made, in these researches, of the formation 
of lead sulphate ; and yet its presence is fully 
established, and the part it plays in local action 
is clearly demonstrated. The slow conversion 
of the peroxide into sulphate on the negative 
plate, with the circuit open, explains the grad- 
ual fall of electromotive force; while the re- 
sidual charge appears to be fully aceounted for 
by the two related facts of the formation of a 
small amount of peroxide on the positive plate 
during the discharge, producing electrical equi- 
librium before the peroxide on the negative 
plate is exhausted, and the subsequent conver- 
sion of this peroxide into sulphate, thus re- 
establishing a difference of potential. The 
formation of highly resistant sulphate from 
peroxide on the negative plate, and from metal- 
lic lead on the positive, accounts for Planté’s 
observation that a cell long disused acquires 
great internal resistance, and charges again 
with difficulty. It seems highly probable, how- 
ever, that the skill acquired by Planté in ‘ form- 
ing’ his cells enables him to so modify the 
physical character of the surfaces of the lead 
plates that the sulphate plays a less important 
part in the final chemical action in his cell than 
it does in the experiments of less skilled phy- 
sicists. Thus Professor Barker says of one of 
his Planté cells, ‘‘ Not a trace of sulphate has 
been formed in it apparently, though it has 
been in use for six months.”’ ? 
It would be pleasant to express as high an 
opinion of M. Planté’s explanations of elec- 
trical phenomena in nature as of his researches : 
but this is impossible; for while he gives a 
possible explanation of ball-lightning, and other 
1 Nature, xxv. 221, 461; xxvi. 251, 602. 
2 Proc. Amer. AS8soc., XXXi. 217. 
