Bacon of the chancellorship and of the Novum Organum may not wane, but Bacon of the prison cell and the Opus Majus steadily approaches him in brightness.
More than three centuries before Francis Bacon advocated the experimental method, Roger Bacon practised it, and the results as now revealed are wonderful.

He wrought with power in many sciences, and his knowledge was sound and exact.

By him, more than by any other man of the Middle Ages, was the world brought into the more fruitful paths of scientific thought--the paths which have led to the most precious inventions; and among these are clocks, lenses, and burning specula, which were given by him to the world, directly or indirectly.

In his writings are found formulae for extracting phosphorus, manganese, and bismuth.

It is even claimed, with much appearance of justice, that he investigated the power of steam, and he seems to have very nearly reached some of the principal doctrines of modern chemistry.