In 1845 and 1846, he acted as assistant to Raffaele Piria (1815–1865), known for his work on salicin, and who was then professor of chemistry at Pisa and subsequently occupied the same position at Turin.

On the collapse of the insurgents, Cannizzaro escaped to Marseille in May 1849, and, after visiting various French towns, reached Paris in October.

Cloez (1817–1883) made his first contribution to chemical research, in 1851, when they prepared cyanamide by the action of ammonia on cyanogen chloride in ethereal solution.

There, he spent ten years studying aromatic compounds and continuing to work on amines, until in 1871 when he was appointed to the chair of chemistry at the University of Rome.

[5] Apart from his work on organic chemistry, which includes also an investigation of santonin, Cannizzaro rendered great service to chemistry with his 1858 paper Sunto di un corso di Filosofia chimica, or Sketch of a course of chemical philosophy, in which he insisted on the distinction, previously hypothesized by Amadeo Avogadro, between atomic and molecular weights.