70 THE AMERICAN JOURNAL OF SOCIOLOGY
Mental derangement is rare among animals and primitive peoples, whose activity is chiefly muscular and devoted to secur- ing food. The same is true where there exist strong demarka- tions between classes of the population. Thus in 1862 in the United States the proportion in ten thousand insane was as fol- lows:
Among the whites - 0.75
Among the enfranchised negroes - 0.71
Among the slave negroes - - o.io
In France the proportion of insane in ten thousand was as
follows :
Liberal professions - - 3.10
Officers - i . 05
Non-commissioned officers - - 0.72
Merchants - 0.42
Soldiers - - 0.33
In Paris there was i case of insanity for every 302 inhabit- ants; in the surrounding country, only I for 1,474. In Nancy the proportion was i to 500 inhabitants; in the remainder of the country, only I for 1,438 inhabitants. In general, the percentage of insanity increases more rapidly in France and Belgium than the population. The proportion of insane in France for 1,000 inhabitants was in :
1835 - 0.43
1841 0.58
1851 - - 1.25
1880 2.37
In England from 1845 to l %79 the population increased 45 per cent.; the number of insane, 250 per cent., or more than five and one-half times faster. In Ireland the proportion of mental derangement was 0.76 per 1,000 inhabitants; ten years later, in 1871, 1.35 per 1,000. It is necessary to take into consideration that in twenty years two million individuals, forming the most energetic and healthy part of the people, left this unfortunate country.
In the United Kingdom, according to an official report, the following was the proportion of insane :
