In those days, "surgeons operated in blood-stiffened frock coats – the stiffer the coat, the prouder the busy surgeon", "pus was as inseparable from surgery as blood", and "Cleanliness was next to prudishness". He quotes Sir Frederick Treves on that era: "There was no object in being clean...Indeed, cleanliness was out of place. It was considered to be finicking and affected. An executioner might as well manicure his nails before chopping off a head".
Source : http://en.wikipedia.org/wiki/Robert_Liston , 5th Paragraph.