AN ESSAY ON LONGEVITY. 125 



greatly changed for what is happier and better in 

 the future consolidation and development of that 

 great people. 



19. Duration of Life in past Time. 



Under this heading, there is little more to be said 

 than was contained in a celebrated but brief chapter. 

 ' There is nothing known ' of the duration of life in 

 past time. A few years since it was the belief, based 

 upon supposed statistical facts, that the potential 

 longevity of man, that is, the expectation of life in 

 the higher ages, was increasing and had been in- 

 creasing for a hundred years. Dr. Farr has fully 

 exposed the fallacy involved in this supposition, 

 which was due to life-tables, erroneously constructed 

 by Dr. Price (to whom, nevertheless, credit is due as 

 a vital statistician), from the mortuary records of the 

 town of Northampton. Dr. Farr has shewn that a 

 table constructed by Price's method gives the same 

 results to-day for Northampton as it did in the 

 celebrated doctor's time. Moreover, the statistics of 

 Sweden, which are very ample, extend from the 

 middle of the eighteenth century, and furnish no in- 

 dication whatever of a change. Some few facts have 

 been adduced by Dr. Guy, which tend to shew a 

 slight fluctuation in longevity in past centuries (see 

 Tables K), but are really too few in number to allow 

 of any generalization by even the most venturesome. 



