MAN. 



grow for thirty years, may live ninety or a hundred ; but a 

 dog, whose growth terminates in two or three years, lives only 

 ten or twelve years. The same observation is applicable to 

 most animals. Fishes continue to grow for a great number 

 of years. Some of them, accordingly, live during several 

 centuries, because their bones and cartilages seldom acquire 

 the density of those of other animals. It may, therefore, be 

 considered as a general fact, that large animals live longer 

 than small ones, because the former require more time to 

 complete their growth. Thus the causes of our dissolution 

 are inevitable ; and it is equally 'impossible to retard that fatal 

 period, as to change the established laws of nature. When 

 the constitution is sound, life may, perhaps, by moderating 

 the passions, and by temperance, be prolonged a few years. 

 But the varieties of climate, and the mode of living, make 

 no material differences with regard to the period of our 

 existence, which is nearly the same in the European, the 

 Negro, the Asiatic, the American, the civilized man and the 

 savage, the rich and the poor, the citizen and the peasant. 

 Neither does the change of food, or of accommodation, make 

 any change in the duration of life. Men who are fed on 

 raw flesh or dried fish, on sago or rice, on cassada or roots, 

 live as long as those who use bread and prepared victuals. 

 If luxury and intemperance be excepted, nothing can alter 

 those laws of mechanism which invariably determine the 

 number of our years. Any little diiferences which may be 

 remarked in the term of human life, seem to be chiefly owing 

 to the quality of the air. In general, there are more old men 

 in high than in low countries. The mountains of Scotland, of 

 Wales, and of Switzerland, have furnished more examples of 

 longevity than the plains of Holland, Flanders, Germany, or 

 Poland. ])ut, if we take a survey of mankind, whatever be 

 the climate they inhabit, or their mode of living, there is no 

 very essential difference in the duration of life. When men are 

 not cut off by accidental diseases, individuals may every where 

 be found who live ninety or a hundred years. Our ancestors, 

 with few exceptions, never exceeded this period ; and, since 

 the days of David, king of the Jews, it has undergone no 

 variation. Beside accidental diseases, which are more fre- 

 quent as well as more dangerous, in the latter periods of life, 

 old men are subjected to natural infirmities that originate 

 solely from a decay of the different parts of the body. The 

 muscles lose their tone, the head shakes, the hands tremble, 

 the limbs totter, the sensibility of the nerves is blunted, the 



