36 MAMMALIA — MAN. 



The strength of man is very considerable, when matured by practice. 

 "We are assured that the porters of Constantinople carry burthens of not 

 less weight than nine hundred pounds ; and Mr Desaguliers tells us of a 

 man, who by distributing a certain number of weights, in such a manner 

 that every part of his body bore its share, was able to support a weight of 

 two thousand pounds, in an upright posture. 



The strength of a man may be still farther estimated by the continuance 

 of his labor, and by the agility of his motions. Men who are exercised in 

 running, outstrip horses, or at least continue their speed for a greater length 

 of time. In a journey, also, a man will walk down a horse; and after they 

 have proceeded together for several days, the horse will be quite tired, and 

 the man will be as fresh as at the beginning. The royal messengers 

 of Ispahan, who are runners by profession, go thirty-six leagues in fourteen 

 or fifteen hours. Travellers assure us that the Hottentots outrun lions 

 in the chase ; and that the savages who hunt the elk, pursue with such 

 f-peed this animal, which is as fleet as a stag, that they at last tire it down 

 and take it. 



When the constitution of the body is sound, it is probably possible, by 

 moderation in the passions, temperance, and sobriety, to lengthen out the 

 period of life for a few years. But even of this there seems an uncertainty. 

 Men no doubt there are, who have passed the usual period of human exist- 

 ence ; and, not to mention Parr, who lived to the age of one hundred and 

 fifty-two, and Jenkins, to that of one hundred and sixty-nine, as recorded in 

 the Philosophical Transactions, we have many instances of the prolongation 

 of life to one hundred and ten, and even to one hundred and twenty years. 

 Yet this longevity was occasioned by no peculiar art or management. On 

 the contrary, it appears that the generality of such long livers were peasants, 

 accustomed . to the greatest fatigues, huntsmen, or laborers; men, in fact, 

 who had employed their whole bodily strength, and even abused it, if to 

 abuse it be possible, otherwise than by continual idleness and debauchery. 



If, in the duration of life, there is any difference to be found, it ought 

 seemingly to be ascribed to the quality of the air. In elevated situations, 

 it has been observed, there are commonly found more old people than in 

 such as are low. The mountains of Scotland and Wales, of Auvergne and 

 Switzerland, have furnished more instances of extreme longevity, than the 

 plains of Holland or Flanders, of Germany or Poland. In general, however, 

 the period of human existence may be said to be the same in every country. 

 If not cut off by accidental diseases, man is found to live to the years of 

 ninety or a hundred. Beyond that date our ancestors did not live ; nor has 

 it in any degree varied since the time of David. 



From a careful inspection of the registers of burials, in a certain number 

 of country parishes in France, compared with the mortality of Paris, the 

 following table has been made out, of the probable duration of human life. 



