In Frankenstein, Chapter 2, what sort of science is Victor learning from Agrippa, Paracelsus, and Albert Magnus?

In Chapter Two, we are introduced to Victor's fascination with natural philosophy.

But the cursory glance my father had taken of my volume by no means assured me that he was acquainted with its contents, and I continued to read with the greatest avidity. When I returned home my first care was to procure the whole works of this author, and afterwards of Paracelsus and Albertus Magnus. I read and studied the wild fancies of these writers with delight; they appeared to me treasures known to few besides myself. I have described myself as always having been imbued with a fervent longing to penetrate the secrets of nature. In spite of the intense labour and wonderful discoveries of modern philosophers, I always came from my studies discontented and unsatisfied. Sir Isaac Newton is said to have avowed that he felt like a child picking up shells beside the great and unexplored ocean of truth. Those of his successors in each branch of natural philosophy with whom I was acquainted appeared even to my boy's apprehensions as tyros engaged in the same pursuit.