At that time John Baptist Porta was conducting his investigations, and, despite a considerable mixture of pseudo-science, they were fruitful.

His was not "black magic," claiming the aid of Satan, but "white magic," bringing into service the laws of nature--the precursor of applied science.

His book on meteorology was the first in which sound ideas were broached on this subject; his researches in optics gave the world the camera obscura, and possibly the telescope; in chemistry he seems to have been the first to show how to reduce the metallic oxides, and thus to have laid the foundation of several important industries.

He did much to change natural philosophy from a black art to a vigorous open science.
He encountered the old ecclesiastical policy.

The society founded by him for physical research, "I Secreti," was broken up, and he was summoned to Rome by Pope Paul III and forbidden to continue his investigations.
So, too, in France.