Schack August Steenberg Krogh (pronounced Krawg) was born on November 15, 1874, in Grenaa, Jutland. Throughout his life Krogh was active in both zoology and human physiology, accomplishing his major discoveries in the physiology of respiration.

Krogh attended school at the Gymnasium at Aarhus, and then went on to the University of Copenhagen in 1893. He first entered Copenhagen with the intention of studying physics and medicine, but under the influence of zoologist William Sorensen, he changed to the study of zoology and physiology. So slash rensen had advised Krogh to attend the lectures of Christian Bohr, an expert in circulatory and respiratory physiology. After attending Bohr's lectures at Copenhagen, Krogh began to work in Bohr's laboratory in 1897, and after receiving his master of science degree in 1899, he became Bohr's laboratory assistant.

One of Krogh's earliest achievements was his invention of a microtonometer--an instrument that measures gas pressure in fluids--which he...