"Pleasures flit by -- they are only for yourself; work leaves a mark of long-lasting joy, work is for others."

"I consider it my duty to warn against this tendency to make a science of alchemy."

"The spirit of scientific inquiry must be cultivated in all children."

"The future of the Russian nation lies in the hands of the schoolmaster and the priest."

"The knowledge of the properties of the elements is the foundation of all chemistry."