http://galton.org
<<prevThe Art of Travel by Francis Galton : image 0199next>>

OCR Rendition - approximate

Recognized HTML document

I go   Art of Travel.

an assimilating machine of limited performance, and must be fed with food that it can digest ; it is not enough that the food should contain nutritious matter, if that matter should be in an indigestible form. Burke and Wills perished from sheer inability to digest the seeds upon which the Australian savages lived ; and Gardiner's party died of starvation in Tierra del Fuego, because they could not digest the shell-fish which form a common article of diet of the natives of that country. The question of diet must then be limited to food that is perfectly digestible by the traveller. It remains to learn how much nourishment is contained in different kinds of digestible food. Dr. Smith has recently written an elaborate essay on this subject, applying his inquiries chiefly to the food of the poor in England ; but for my more general purpose, as it is impossible to do justice to a large and imperfectly understood subject, in the small space I can give to it, it will be better that I should reprint the results given in my previous edition. These are principally extracted from a remarkable paper by Dr. Christison, inserted in the Bluebook Report of the Commission of Inquiry on Crimean matters, in which the then faulty dietary of our soldiers was discussed. It appears 1st, that a man of sedentary life can exist in health on seventeen

ounces per day of real nutriment ; that a man engaged in

active_ life requires fully twenty-eight ounces per day ; and, during severe labour, he requires thirty ounces, or even more. 2ndly, that this nutriment must consist of three-quarters, by weight, of one class of nutritive principles, (C), and one quarter of another class of nutritive principles, (N); 3rdly, that all the articles of common food admit of being placed, as below, in a Table, by which we see at a glance how much nutriment of class C, and how much of class N, is found in 100 parts, gross weight, of any of them. Thus, by a simple computation, the effective value of a dietary may be ascertained. Class C, are the carboniferous principles, that maintain respiration ; Class N, are the nitrogenous principles, that repair waste of tissue. N will partly replace C, but at a great waste : C will not replace N.

A large number of diets such as those of various armies and navies, of prisons and infirmaries, and of the ordinary diets of different classes of people, have been examined by the

)F - www.fastio.com