Th: Jefferson.




LETTER XII.--TO DR. GEM


THOMAS JEFFERSON TO DR. GEM.

The hurry in which I wrote my letter to Mr. Madison, which is in your
hands, occasioned an inattention to the difference between generations
succeeding each other at fixed epochs, and generations renewed daily
and hourly. It is true that in the former case, the generation when
at twenty-one years of age, may contract a debt for thirty-four
yours, because a majority of them will live so long. But a generation
consisting of all ages, and which legislates by all its members above
the age of twenty-one years, cannot contract for so long a time, because
their majority will be dead much sooner. Buffon gives us a table of
twenty-three thousand nine hundred and ninety-four deaths, stating
the ages at which they happened. To draw from these the result I have
occasion for, I suppose a society in which twenty-three thousand nine
hundred and ninety-four persons are born every year, and live to the age
stated in Buffon's table. Then, the following inferences may be drawn.
Such a society will consist constantly of six hundred and seventeen
thousand seven hundred and three persons, of all ages. Of those living
at any one instant of time, one half will be dead in twenty-four years
and eight months. In such a society, ten thousand six hundred and
seventy-five will arrive every year at the age of twenty-one years
complete. It will constantly have three hundred and forty-eight thousand