Johann Nathanael Lieberkühn

Following this he returned to Berlin as a member of the Collegium medico-chirurgicum,[1] the body charged with improving the teaching and science of medicine in the Holy Roman Empire, making mathematical and optical instruments and working as a professor and medical doctor.

Besides his physiological work, Lieberkühn was most known for his preparation of medical specimens—these were still presented up to the nineteenth century, especially in Moscow, as masterpieces.

His specimens were prepared primarily with injections of wax-containing fluids into body cavities, creating relatively durable shapes.

The Crypts of Lieberkühn (intestinal glands) are named for him; he first described these in detail in De fabrica et actione vollorum intestinorum tenuium hominis, in 1745.

[2] His custom microscopes for studying blood vessels were called "Wundergläser", ‘wonder-glasses’ by his contemporaries.