Semmelweis soon became convinced that the solution to the problem of puerperal fever lay in the difference between these figures and he was determined to find the reason for this discrepancy. He set himself to the study of all the case histories from 1789, the year of foundation of the clinic. The second clinic was founded in 1833 after the division of the lying-in hospital into two clinics. Between 1833 and 1839 mortality had been equally high in both clinics. A definite change was noticeable from 1840 onwards when the first clinic was available to medical students only, and the second clinic to midwifery students only.
Puerperal disease remains a mystery, only the number of the dead is a palpable fact.
Semmelweis observed that the pathological findings in the cadavers of the mothers and in their babies were identical. The same changes were seen on the peritoneum and viscera and they had the same signs of inflammation. He had of course come to the conclusion that the babies had died of the same disease as their mothers - pyaemia. Since others, other than recently delivered women, could contract puerperal fever and die as a result, puerperal fever could not be considered a disease of puerperal patients only. Semmelweis had reached this point in his observations when doctor Kolletschka, professor of forensic medicine, died.