Volume 1

The philosophy of health ; or, an exposition of the physical and mental constitution of man, with a view to the promotion of human longevity and happiness / by Southwood Smith.

  • Smith, Southwood, 1788-1861.
Date:
1847
Catalogue details

Licence: Public Domain Mark

Credit: The philosophy of health ; or, an exposition of the physical and mental constitution of man, with a view to the promotion of human longevity and happiness / by Southwood Smith. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

    125/422 (page 115)
    Considerations, purely physiological, establish this indubitably; but it is curious that a class of facts, totally different from those of a physiological nature, equally prove it; namely, the results ob- tained from the observation of the actual numbers that die at different ages, and the knowledge con- sequently acquired of the progressive decrement of life. Mortality is subject to a law, the operation of which is as regular as that of gravitation. The labours of my valued friend Mr. Finlaison, the actuary of the National Debt, have not only deter- mined what that law is in relation to different na- tions at different periods of their history, but this celebrated calculator has also invented a striking mode of expressing and representing the fact. He constructed a chart on which 100 perpendicular lines, answering to the respective ages of human life, are laid down and numbered in succession. These are crossed at right angles by 500 horizontal lines; so that, in the manner of musical notation, a point may be laid down either on the horizontal line, or on the space between any two of them: and thus, 1000 points may be laid down on each of the perpendicular lines. The horizontal lines are in like manner numbered from 1 to 1000, ascending from the base. Taking any observation which shows the number of living persons that commence, and in like manner the number that die in each particular year of human life, the cal- culator reduced by the rule of three every such