This stamp has a hidden date in the bottom-right corner.
These two stamps feature two significant secondary industries of Canada. The 20-cent stamp replaced the 1952 issue of the same denomination. The 25-cent stamp is a new denomination; in fact, this is the first time that Canada has ever issued a 25-cent postage stamp. Apart from paying registration and postage charges, the 25-cent stamps may be used to prepay charges on overseas mail to certain destinations.
The design depicting a laboratory vessel is illustrative of the scientific equipment used widely for research in the chemical industry. A representative chemical plant appears in the lower part of the glass container. Glass tubing extending from the vessel encloses at enlarged ends a head of wheat to represent agriculture and a symbolic industrial plant. This design emphasizes the significance of chemistry in our daily lives and in the nation's development.
This stamp has the initial of the designer in the top-left corner. The initial P belongs to Alan L. Pollock.