The Wellcome Library belongs to the Wellcome Foundation. This how the Collection describes itself:

Wellcome Collection is a free museum and library that aims to challenge how we all think and feel about health. Through exhibitions, collections, live programming, digital, broadcast and publishing, we create opportunities for people to think deeply about the connections between science, medicine, life and art. We are part of the Wellcome Trust, which was established under Sir Henry Wellcome’s will in 1936. Wellcome exists to improve health by helping great ideas to thrive. We support researchers, we take on big health challenges, we campaign for better science, and we help everyone get involved with science and health research. We are a politically and financially independent foundation.

Here is what they say about their library collection:

Whatever aspect of medical history you’re interested in, we’ve got it covered – from allergies and anatomy to war surgery and women’s health. There’s material on everything you’d expect – obesity, gender and plastic surgery, for example. But there’s also plenty on subjects you probably wouldn’t – like alchemy, witchcraft or vampires.

You can learn more about the museum and the library from their website: https://wellcomecollection.org/pages/Wuw19yIAAK1Z3Smm

We will be touring the library and meeting with some library staff to hear about their work and backgrounds at 2:00Pm August 28