An exhaustive account by H. Sueur and a large number of other reports offer us very full information regarding the condition of health in Paris during the siege, since the administrative apparatus never stopped running. The approach of the German armies caused numerous well-to-do citizens to leave the city; some went south, some to Switzerland, and some to England. Sueur estimates their number from the reports of the railroad companies at 300,000. On the other hand, a large number of the inhabitants of the surrounding country sought refuge in the city; their number is estimated at 180,000. Furthermore, the size of the garrison was considerably increased; the number of men in the regular army on November 4, 1870, is estimated at 236,941, and this does not include 8,000 men in the First Division of the First Corps. To the above, moreover, must be added the number of soldiers who died between the beginning and the end of the siege. Thus the number of men in the regular army at the beginning of the siege was some 246,000; of these some 56,000 were already in the city in the middle of the summer, while the remaining 190,000 arrived later. Accordingly, the total number of people in the city shortly before the siege began was increased by 70,000. Legoyt estimated the population of the city on July 1, 1870, at 1,890,000, so that on the opening day of the investment there were 1,960,000 (in round numbers, 2,000,000) people in Paris. The arrival of the 190,000 soldiers altered the composition of the population, since the increase augmented only the number of males between the ages of 20 and 40. A severe epidemic of small-pox raged in Paris, as stated above, even before the siege took place. In the first part of the siege, moreover, the disease raged with even greater fury in the city, since most of the young newly-enlisted mobile guards had never been vaccinated. The maximum of deaths caused by it were reported between November 6 and November 27. We have already described the course of the small-pox epidemic in Paris.[345] It was influenced neither by hunger nor by cold, but developed chiefly for the reason that it was impossible to congregate and isolate the large number of unvaccinated and susceptible persons.