The pestilence continued to rage even after the surrender of the stronghold, and did not begin to abate until the latter part of January. Although the Prussian troops were not quartered in the city, and entered it only in the day-time, the pestilence nevertheless spread to them and carried away more than 300 men in the course of three months. Not until the end of February did the pestilence among the civil inhabitants begin to abate; the mortality was still high in March, but in April it sank to normal again. According to Richter, two-thirds of the patients in the military lazaret were suffering from ‘colliquative, dysenteric diarrhoea’, and only one-third from ‘true typhus’, whereas among the civil inhabitants the latter was by far the more common. There were two forms of diarrhoea observed; it appeared either as an acute attack of dysentery, which rarely lasted longer than two weeks and then terminated in either death or recovery, or else as a chronic, dysenteric diarrhoea, which caused general weakness and finally death. Typhus fever began always with a frequently recurring chill, and with a violent headache and general indisposition; this was followed by a stage of dry fever, accompanied by stupor, dizziness, and often wild delirium; as a rule the first few days were characterized by obstinate constipation, and bleeding at the nose was very common. Later on, somnolence manifested itself, and the original constipation changed to a copious, fetid diarrhoea. Petechiae appeared frequently, but not invariably; at first small, bright-red spots showed themselves, and later on they assumed a darker colour, grew larger, and finally turned black. Their size varied considerably; sometimes they were the size of a pin-head, while often they were from one to one-and-a-half centimetres in diameter. Most of the patients died between the tenth and fifteenth days; but if the disease progressed favourably, signs of improvement usually showed themselves suddenly on the fourteenth or fifteenth day; as a rule, convalescence was of short duration.