<s>
The	O
Leclanché	B-Algorithm
cell	I-Algorithm
is	O
a	O
battery	O
invented	O
and	O
patented	O
by	O
the	O
French	O
scientist	O
Georges	O
Leclanché	O
in	O
1866	O
.	O
</s>
<s>
The	O
battery	O
contained	O
a	O
conducting	O
solution	O
(	O
electrolyte	O
)	O
of	O
ammonium	O
chloride	O
,	O
a	O
cathode	O
(	O
positive	O
terminal	O
)	O
of	O
carbon	O
,	O
a	O
depolarizer	B-Algorithm
of	O
manganese	O
dioxide	O
(	O
oxidizer	O
)	O
,	O
and	O
an	O
anode	O
(	O
negative	O
terminal	O
)	O
of	O
zinc	B-Application
(	O
reductant	O
)	O
.	O
</s>
<s>
The	O
chemistry	O
of	O
this	O
cell	O
was	O
later	O
successfully	O
adapted	O
to	O
manufacture	O
a	O
dry	B-Algorithm
cell	I-Algorithm
.	O
</s>
<s>
In	O
1866	O
,	O
Georges	O
Leclanché	O
invented	O
a	O
battery	O
that	O
consisted	O
of	O
a	O
zinc	B-Application
anode	O
and	O
a	O
manganese	O
dioxide	O
cathode	O
wrapped	O
in	O
a	O
porous	O
material	O
,	O
dipped	O
in	O
a	O
jar	O
of	O
ammonium	O
chloride	O
solution	O
.	O
</s>
<s>
The	O
dry	B-Algorithm
cell	I-Algorithm
form	O
was	O
used	O
to	O
power	O
early	O
telephones	O
—	O
usually	O
from	O
an	O
adjacent	O
wooden	O
box	O
affixed	O
to	O
the	O
wall	O
—	O
before	O
telephones	O
could	O
draw	O
power	O
from	O
the	O
telephone	O
line	O
itself	O
.	O
</s>
<s>
The	O
Leclanché	B-Algorithm
cell	I-Algorithm
could	O
not	O
provide	O
a	O
sustained	O
current	O
for	O
very	O
long	O
;	O
in	O
lengthy	O
conversations	O
,	O
the	O
battery	O
would	O
run	O
down	O
,	O
rendering	O
the	O
conversation	O
inaudible	O
.	O
</s>
<s>
Leclanché	O
first	O
,	O
and	O
Carl	O
Gassner	O
later	O
,	O
both	O
strived	O
to	O
transform	O
the	O
original	O
wet	O
cell	O
into	O
a	O
more	O
portable	O
and	O
more	O
efficient	O
dry	B-Algorithm
cell	I-Algorithm
.	O
</s>
<s>
Porous	O
pot	O
cell	O
In	O
Leclanché	O
's	O
original	O
cell	O
the	O
depolarizer	B-Algorithm
(	O
in	O
fact	O
,	O
the	O
oxidizing	O
agent	O
in	O
the	O
cell	O
)	O
,	O
consisting	O
of	O
crushed	O
manganese	O
dioxide	O
,	O
is	O
packed	O
into	O
a	O
pot	O
,	O
and	O
a	O
carbon	O
rod	O
is	O
inserted	O
to	O
act	O
as	O
the	O
cathode	O
(	O
reduction	O
reaction	O
)	O
.	O
</s>
<s>
The	O
anode	O
(	O
oxidation	O
reaction	O
)	O
,	O
which	O
is	O
a	O
zinc	B-Application
rod	O
,	O
is	O
then	O
immersed	O
along	O
with	O
the	O
pot	O
in	O
a	O
solution	O
of	O
ammonium	O
chloride	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
zinc	B-Application
rod	O
is	O
replaced	O
by	O
a	O
zinc	B-Application
cylinder	O
to	O
give	O
a	O
larger	O
surface	O
area	O
.	O
</s>
<s>
Starch	B-Application
addition	O
In	O
1876	O
,	O
Georges	O
Leclanché	O
added	O
starch	B-Application
to	O
the	O
ammonium	O
chloride	O
electrolyte	O
in	O
an	O
effort	O
to	O
better	O
jellify	O
it	O
.	O
</s>
<s>
Improved	O
dry	B-Algorithm
cell	I-Algorithm
In	O
1888	O
,	O
a	O
German	O
physician	O
,	O
Carl	O
Gassner	O
,	O
improved	O
the	O
jellification	O
process	O
and	O
produced	O
a	O
more	O
portable	O
dry	B-Algorithm
cell	I-Algorithm
by	O
mixing	O
plaster	O
and	O
hydrophilic	O
chemicals	O
with	O
the	O
ammonium	O
chloride	O
electrolyte	O
.	O
</s>
<s>
The	O
redox	O
reaction	O
in	O
a	O
Leclanché	B-Algorithm
cell	I-Algorithm
involves	O
the	O
two	O
following	O
half-reactions	O
:	O
</s>
<s>
The	O
chemical	O
process	O
which	O
produces	O
electricity	O
in	O
a	O
Leclanché	B-Algorithm
cell	I-Algorithm
begins	O
when	O
zinc	B-Application
atoms	O
on	O
the	O
surface	O
of	O
the	O
anode	O
oxidize	O
,	O
i.e.	O
</s>
<s>
When	O
the	O
cell	O
is	O
connected	O
in	O
an	O
external	O
electrical	O
circuit	O
,	O
the	O
excess	O
electrons	O
on	O
the	O
zinc	B-Application
anode	O
flow	O
through	O
the	O
circuit	O
to	O
the	O
carbon	O
rod	O
,	O
the	O
movement	O
of	O
electrons	O
forming	O
an	O
electric	O
current	O
.	O
</s>
<s>
produced	O
by	O
a	O
Leclanche	B-Algorithm
cell	I-Algorithm
is	O
1.4	O
volts	O
,	O
with	O
a	O
resistance	O
of	O
several	O
ohms	O
where	O
a	O
porous	O
pot	O
is	O
used	O
.	O
</s>
<s>
The	O
Leclanché	B-Algorithm
battery	I-Algorithm
wet	O
cell	O
was	O
the	O
forerunner	O
of	O
the	O
modern	O
zinc	B-Algorithm
–	I-Algorithm
carbon	I-Algorithm
battery	I-Algorithm
(	O
a	O
dry	B-Algorithm
cell	I-Algorithm
)	O
.	O
</s>
<s>
The	O
addition	O
of	O
zinc	B-Application
chloride	O
to	O
the	O
electrolyte	O
paste	O
raises	O
the	O
e.m.f.	O
</s>
<s>
Later	O
developments	O
dispensed	O
with	O
the	O
ammonium	O
chloride	O
completely	O
,	O
giving	O
a	O
cell	O
that	O
can	O
endure	O
more	O
sustained	O
discharge	O
without	O
its	O
internal	O
resistance	O
rising	O
as	O
quickly	O
(	O
the	O
zinc	B-Application
chloride	O
cell	O
)	O
.	O
</s>
