In 1847 Ignaz Semmelweiss, of the Vienna Lying-in Hospital, decided as a result of some of his investigations that puerperal infection was a wound infection, and that the infecting organisms were introduced into the birth canal on the examining finger of the doctor or nurse, after contact with an infected patient or cadaver. Accordingly he required that all vaginal examinations be preceded by washing the hands in chloride of lime, after which precautions the mortality from infection dropped from 10 per cent. to less than 1 per cent. In 1867 Semmelweiss offered his theories and conclusions in a masterly work on this subject, the title of which may be translated as “The Etiology, Conception and Prophylaxis of Child-Bed Fever,” but the actual cause of the disease was still unknown. But about 1879 Pasteur demonstrated what is now known as the streptococcus, in certain patients suffering from puerperal fever. “Pasteur,” wrote M. Roux, “does not hesitate to declare that that microscopic organism (a microbe in the shape of a chain or chaplet) is the most frequent cause of infection in recently delivered women. One day, in a discussion on puerperal fever at the Academy, one of his most weighty colleagues was eloquently enlarging upon the causes of epidemics in lying-in hospitals; Pasteur interrupted him from his place. ‘None of those things cause the epidemic; it is the nursing and medical staff who carry the microbe from an infected woman to a healthy one.’ And as the orator replied that he feared that microbe would never be found, Pasteur went to the blackboard and drew a diagram of the chain-like organism, saying: ‘There, that is what it is like!’ His conviction was so deep that he could not help expressing it forcibly. It would be impossible now to picture the state of surprise and stupefaction into which he would send the students and doctors in hospitals, when, with an assurance and simplicity almost disconcerting in a man who was entering a lying-in ward for the first time, he criticised the appliances, and declared that the linen should be put into a sterilizing stove.”[13] Slowly, but very slowly, the teachings of these earnest men were adopted by the medical profession, with the result that in well-conducted, modern hospitals the precautions which have been described in preceding chapters are rigidly observed. And to-day, one woman in about 1,000 in such hospitals dies of puerperal infection, instead of one in ten, as in the early days. In the year 1864, 23 per cent. of the patients at the Maternité, in Paris, died of puerperal infection.