Christiaan Huygens acquired Hooke's Micrographia

By mid-1665, two of Leeuwenhoek's mentors, Constantijn and Christiaan Huygens, had copies of Robert Hooke's Micrographia.

In January 1665 Robert Moray wrote to Huygens that he had asked William Davidson to take a copy of Micrographia to Holland. Leeuwenhoek, while living in Amsterdam, had been Davidson's apprentice until 1654.

On 27 February, Christiaan Huygens reported to Moray that it had not arrived but that his father had a copy that his father had found fascinating. Christiaan Huygens doubted that much could come of microscopic investigations.

On 26 March, Christiaan Huygens wrote to his father that he had received the book, presumably from Davidson. Christiaan found it, especially the figures, more interesting than he had expected to. However, he was not convinced by Hooke's experiences and indicated that he would have to try himself.

On 17 April, Johannes Hudde wrote to Christiaan Huygens, thanking him for having translated the "most fundamental matters" (principaalste zaaken) of Micrographia. By this time, Hudde was using single-lens microscopes of his own design. He told Huygens that if he had time, he would learn English just to read Micrographia or to read about Robert Boyle's experiments.

It was through one or both of the Huygenses that Leeuwenhoek may well have had access to this book, and presumably Christiaan's translation. In Leeuwenhoek's first letter to the Royal Society, eight years later, he replicated and extended several of Hooke's observations from Micrographia. He may also have been influenced by Hooke's description of how to make and mount a tiny lens.