DOCUMENT

58

OCTOBER

1899 237

tive

elektrische Kerne sind ohne

ponderable

Masse, welche die

thermischen und

elektrischen

Erscheinungen

in

Metallen

bedingen" (Doc.

96).

Though

Einstein

was

aware

of the

difficulties in

explaining magnetism

on

this

basis,

he

believed that Drude

was

"auf dem

richtigen Wege" (Doc.

97).

Einstein continued

to

work

on

his

own

theory

of

thermoelectricity

for

a

time,

but decided

not to

publish

it

(see

Doc.

110).

A paper

by Reinganum[9]

that

derives the Wiedemann-Franz

law

from

more

general

assumptions

than Drude's convinced Einstein

that

the fundamental

principles

of the

electron

theory

were

correct

(Doc.

111).

Nevertheless,

Einstein had

two

specific

objections

to

Drude's version of the

theory

(see

Doc.

115),

as

he

pointed

out in

a

letter

to

Drude

(see

Docs.

110,

112).

He

was

gravely disappointed

by

Drude's

reply

(see

Docs.

114,

115).

The

nature

of Einstein's

objections is

not

known,

but

a

number of

criticisms

of Drude's

theory

were

published.

Reinganum pointed

out

that

the

large

number of

freely

moving charge

carriers

assumed

in

a

metal should

give

rise to

a

much

higher

value of the

specific

heat than

is

observed.[10] He

also noted that Drude did

not

take into

account

the

velocity

distri-

bution of the

charge

carriers. Drude assumed that

currents in

metals

were

carried

by

charges

of both

signs,

while

Thomson's work

suggested

that

such

currents

were

carried

exclusively by

negative

charges.[11]

[9]

Reinganum

1900

(see

Doc.

111,

note

6).

[10]

This

problem

is

mentioned

in

Einstein

1907,

p.

187.

[11]

See

Thomson,

J., 1900.

Other

objections

were

also

raised: Hall discovered

a sign error

in

Drude's calculation of the Thomson

effect,

corrected

in Drude 1902.

Drude's derivation

of the Wiedemann-Franz

law

neglected

the

effect

of the electrical

field

on

collision times

in

calculating

the electrical

conductivity

(see

Seeliger

1921,

which

reviews

criticisms of the

classical electron

theory

of

metals).

58.

To Mileva

Maric

Mailand.

Dienstag

[10

October

1899][1]

L[iebes]

S[üßes?][2]

D[oxerl]!

Jetzt

Sie sind

mir

eine Schöne!

Sitzt schon

ganz gemütlich

4

Tage

im

Examen

&

hat kein Schnauferlein

für

ihren braven Herrn

Kollegen

und

Kaffeesaufbrüderchen. Ist das nicht schauderbar? Ich werde mir

eine

Schauer-

predigt

einstudieren und

sie

Ihnen

am

nächsten

Montag persönlich

halten,

und

zwar

in

aller Frühe. Und

wenn

das

Mädchen

sagt,

Sie seien

ausgegangen

&

ich

sehe

Ihre

gewichsten

Stiefelchen

vor

der

Thüre-wie

das

so

manchmal

passieren

soll-dann

warte ich

einfach noch

ein bissel

oder

lasse

mich rasieren.

ALS

(CLE).

[1] Dated

by

the

references in this

letter and

in

the

preceding

one

to

Einstein's

return to

Zurich.

[2]

Underlined

twice in

the

original.