The Science Book

124

THE ARTIFICIAL PRODUCTION

OF ORGANIC SUBSTANCES

FROM INORGANIC

SUBSTANCES

FRIEDRICH WÖHLER (1800–1882)

I

n 1807, the Swedish chemist

Jöns Jakob Berzelius suggested

that a fundamental difference

existed between the chemicals

involved in living things and all

other chemicals. These unique,

“organic” chemicals, Berzelius

argued, could only be assembled by

living things themselves and, once

broken down, could not be remade

artificially. His idea conformed with

the prevailing theory known as

“vitalism,” which held that life was

special and that living things were

IN CONTEXT

BRANCH

Chemistry

BEFORE

1770s Antoine Lavoisier and

others show that water and

salt can return to their former

state after heating, but sugar

or wood cannot.

1807 Jöns Jakob Berzelius

suggests a fundamental

difference between organic

and inorganic chemicals.

AFTER

1852 British chemist Edward

Franklin suggests the idea of

valency, the ability of atoms to

combine with other atoms.

1858 British chemist

Archibald Couper suggests the

idea of bonds between atoms,

explaining how valency works.

1858 Couper and August

Kekulé propose that organic

chemicals are made by chains

of bonded carbon atoms with

side branches of other atoms.

endowed with a “life force” beyond

the understanding of chemists.

So it came as a surprise when

the pioneering experiments of a

German chemist named Friedrich

Wöhler showed that organic

chemicals are not unique at all,

but behave according to the same

basic rules as all chemicals.

We now know that organic

chemicals comprise a multitude of

molecules based on the element

carbon. These carbon-based

molecules are indeed essential

components of life, but many can

be synthesized from inorganic

chemicals—as Wöhler discovered.

Chemistry rivals

Wöhler’s breakthrough came about

because of a scientific rivalry. In

the early 1820s, Wöhler and fellow

chemist Justus von Liebig both

came up with identical chemical

analyses for what seemed to be two

very different substances—silver

fulminate, which is explosive, and

silver cyanate, which is not. Both

men assumed that the other had

the wrong results, but after

corresponding, they found they

were both right. This group of

compounds led chemists to realize

that substances are defined not just

Widely used in fertilizers, urea is

rich in nitrogen, which is essential to

the growth of plants. Synthetic urea,

first made by Wöhler, is now a key raw

material in the chemical industry.