Among the Italians extreme congestion had manifested itself as long ago as the decade of the nineties. The average density of population in the Italian quarter of the North End of Boston was said to be nearly 1.40 persons per room.[201] In the Italian quarter of Philadelphia investigators found 30 Italian families, numbering 123 persons, living in 34 rooms. In some of the Italian tenements in this city, lamps were kept burning all day in some of the rooms, where day could scarcely be distinguished from night.[202] The Jews at this time were only a little less densely crowded than the Italians. In 1891 nearly one fourth of the whole number of Jews living in two of the precincts of the North End of Boston were living with an average of more than two persons to a room and were found to be very uncleanly in the care of their homes. Among the Irish an average of 1.24 persons per room was found in Boston in 1891. On the whole they kept their tenements cleaner than did the Jews or Italians.[203] Since the beginning of the twentieth century, interest in the slum population of our cities has centered itself about the Slavic and other races of southeastern Europe, even more than about the Italians and Jews. About one sixth of the entire population of Buffalo, or 80,000 individuals, is Polish. Of these, about 4000 families, representing 20,000 persons, own their homes. They are said to be thrifty, clean, willing, and neglected. Nearly all the Poles live in small one and two story wooden cottages. Good tenement work thirty years ago avoided the serious structural conditions which prevail in most cities. The principal evil now in the Polish section is room-overcrowding. The two-story cottages hold six or more families, while the older one-story cottage was built for four families, though the owner is likely to occupy two of the rear apartments. There are 15,000 of these cottages, all subject to the tenement law. A Pole was recently made health commissioner, and gave promise of being the best incumbent of that office that Buffalo has ever had. That there is plenty of work for him to do may be judged from the description of some of the conditions which prevail.