Victorious in this encounter, he turned to those who urged that anaesthetics were responsible for various kinds of ills such as a tendency to haemorrhage, convulsions, paralysis, pneumonia, and various kinds of inflammatory mischief as well as mental derangement. He combated these contentions until the end of his career; and not only proved that the objections were visionary, but showed that for one of the alleged evils formerly often seen after operations, viz., convulsions, chloroform, far from being a cause, was one of our most powerful remedies. But the professional opponents of anaesthesia were most emphatic in the denunciation of its use in midwifery. Pain in the process of parturition was, they said, "a desirable, salutary, and conservative manifestation of life-force": neither its violence nor its continuance was productive of injury to the constitution. Strong opposition on these grounds came from the Dublin School, and with characteristic boldness Simpson turned to the statistics of their own lying-in hospital to prove his contention that to abolish parturient pain was to diminish the peril of the process. Again the statistics stood him in good stead; he flourished them triumphantly before his opponents, and proceeded to deal with those who asserted that the use of anaesthetics was accompanied by danger to life. He pointed out that, although unquestionably there were some dangers connected therewith, they were insignificant compared with the dangers in both surgery and midwifery which their use averted. Pain itself was a danger; shock in surgery was responsible for many untimely deaths upon the operating table; by preventing these chloroform saved countless lives. His arguments were characterised by painstaking thoroughness and evidenced wide reading. In addressing Professor Meigs, of Philadelphia, he said:--