138 EKRORS REGARDING THE DURATION OF LIFE. 



reader. In his report on the census of Massachusetts, 

 he says " while from the Massachusetts Registration Re- 

 ports it is learned that the average age to which all live is 

 about thirty," he comes within twenty years of the right 

 figure. The most important fact and the easiest obtained 

 is to get the number of the population and the number of 

 deaths. For the City of Salem the deaths for the eleven 

 years, from 1865 to 1875, were 54.07, the population 

 25,958 or 1.89: to 100 living; if we take the average 

 of the population for the eleven years it is a trifle over two 

 per cent, which would take forty-nine years as the length 

 of a generation in this city. 



Holyoke is considered the most unhealthy city in Mas- 

 sachusetts : the deaths under five years are fifty-two per 

 cent of all the deaths in the city. This is calculated 

 on the births which for the eleven years were 4,065. 

 There were added to the city by immigration during the 

 eleven years, 10,612, of which number sixteen and one- 

 half per cent were under five years of age, which makes 

 1,750 added to the city by immigration, making with the 

 births, which were 4,065, 5,815 to draw the deaths under 

 five from. Now, if 5,815 gives fifty-two per cent deaths 

 under five years, what will 4,065 give? answer, thirty-six 

 per cent, just the average of the whole state. There 

 were added to the state by immigration in the eleven 

 years, 273,044, of this number 255,992 were added in 

 cities. Of this 255,992, there were added to the cities 

 42,238 under five years of age in the eleven years; that 

 is what makes the deaths under five greater in the cities, 

 42,238 being distributed in the different cities according 

 to the increase of population ; this number is in addition 

 to the births of the cities. Our registration officers have 

 left out entirely the number under five that have been 

 added to the state by immigration, and many blunders 



