His study of chemistry began in Karlsruhe (Germany)
and continued in Zurich (Switzerland), where in his
doctoral thesis in 1890, he explained the difference in
properties of certain nitrogen containing organic
substances on the basis of isomerism He extended vant
Hoff’s theory of tetrahedral carbon atom and modified
it for nitrogen Werner showed optical and electrical differences between
complex compounds based on physical measurements In fact, Werner was
the first to discover optical activity in certain coordination compounds