Final answer:
Ignaz Semmelweis was the physician who linked the high rate of infections in maternity wards to doctors not washing their hands after performing autopsies. His introduction of handwashing practices significantly reduced mortality rates from puerperal fever.
Step-by-step explanation:
The scientist who established a connection between infections in the maternity ward and physicians with unwashed hands coming directly from autopsies was Ignaz Semmelweis. In 1847, Semmelweis observed that the maternity wards staffed by physicians, who also conducted autopsies, had higher mortality rates due to puerperal fever than those staffed by midwives. He inferred that the fever was a contagious disease transmitted by doctors from autopsied bodies. Semmelweis' insistence on the importance of handwashing with chlorinated lime water before examining patients drastically reduced the mortality rate from 18% to 2%, demonstrating that handwashing was an effective method for preventing disease transmission.