102 THE POPULAR SCIENCE MONTHLY. 



would lengthen our list too much to quote from the records of cen- 

 tenarians in other countries. Taking the mean of the censuses from 

 1869 to 1872, we find that Europe (except Russia, Turkey, and a few 

 small states in the south) had in a population of 212,940,376, 17,313,715 

 persons more than sixty, 79,850 more than ninety, and 3,108 more than 

 one hundred years old ; or one person in twelve over sixty, one in 

 2,669 over ninety, and one in 62,503 over a hundred. According to 

 a table we have calculated for fifteen countries of Europe, more women 

 than men attain an extreme old age, and the difference increases with 

 the age. The greatest number of persons over sixty years of age is 

 found in France, but not the greatest number of centenarians. Calcu- 

 lating upon the given age at death, we have found the percentage of 

 those among the deceased who were ninety years old and more to be, in 

 Great Britain, 9 - 73 ; in Sweden, 7*39 ; in France, 6 - 58 : in Belgium ; 

 6-07 ; in Switzerland, 6 ; in Holland, 4 '47 ; in Italy, 3*76 ; in Bavaria, 

 3*42 ; in Prussia, 3*06 ; in Austria, 2*61. 



As to whether the proportion of great longevities is increasing or 

 diminishing, we have information only for France. During the four- 

 teen years, from 1823 to 1837, the mean annual number of persons 

 dying centenarians was 152, or one for 217,105 inhabitants ; during 

 the eight years, from 1852 to 1860, the mean was 111 in a population 

 that had increased twenty per cent. But, although the great ages 

 seem to have diminished, the mean length of life has very sensibly 

 increased, and this is much better. 



A number of centenarians have made their regimen known. Not- 

 withstanding some rare examples to the contrary, temperance, sobriety, 

 and regularity of habits, are of the first importance ; then follow 

 heredity, a relatively comfortable condition, freedom from strong and 

 frequent emotions, residence as far as possible in the country, exer- 

 cise, and a healthy and quiet business. The celebrated but humorous 

 German physiologist, Hoffmann, summarizes the means of reaching a 

 great age as follows : " Avoid excess in everything, respect old habits, 

 even bad ones, breathe a pure air, adapt your food to your temjjera- 

 ment, shun medicines and doctors, keep a quiet conscience, a gay 

 heart, a contented mind." Hevtce Scientijique. 



WORRY. 



Bv Dr. J. MOETIMEE GRANVILLE. 



WHEN a strong and active mind breaks down suddenly, in the 

 midst of business, it is worn out by worry rather than over- 

 work. Brain-labor may be too severe, or ordinary exercise prolonged 

 until it produces serious exhaustion ; but the mere draining of re- 



