OF NATURAL HISTORY. 511 



moft animals. Fifhes continue to grow for a great number 

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

 centuries ; becaufe their bones and cartilages feldom acquire 

 the denfity of thofe of other animals. It may, therefore, be 

 confiJered, as a general fadl, that large animals Hve longer 

 than fmall ones, becaufe the former require more time to 

 complete their growth. Thus the caufes of our diflblution 

 are inevitable 5 and it is equally impoifible to retard that 

 fatal period, as to change the eftablilhed laws of Nature. 

 When the conftitution is found, life may, perhaps, by mode- 

 rating the paifions, and by temperance, be prolonged for a 

 few years. But the varieties of climate, and the modes of 

 living, make no material differences with regard to the peri-r 

 od of our exiftence, which is nearly the fame in the Europe- 

 an, the Negro, the Afiatic, the American, the civilized man 

 and the favage, the rich and the poor, the citizen and the pea* 

 fant. Neitherdoes the difference of food, orof accommodation, 

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

 on raw fleOi or dried fifh, on fago or rice, on caflada or roots, 

 live as long as thofe who ufe bread and prepared vi£luals. 

 If luxury and intemperance be excepted, nothing can alter 

 thofe laws of mechanifm which invariably determine the 

 number of our years. Any little differences which may be 

 remarked in the term of human life, feem to be chiefly ow- 

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

 men in high than in low countries. The mountains of Scot- 

 land, of Wales, and of Switzerland, have furniflied more 

 examples of longevity than the plains of Holland, Flanders, 

 Germany, or Poland. But if we take a furvey of mankind, 

 whatever be the climate they inhabit, or their mode of living, 

 there is fcarcely any difference in the duration of life. 

 When men are not cut off by accidental difeafes, individuals 

 may every where be found who live ninety or an hundred 

 years. Our anceftors, with few exceptions, never exceeded 



