The effects of food upon the civil prisoners, both of the long and short term, have been carefully studied by Christison, Liebig, Barral, and Edwards; and it is conclusively shown by their statistics of the prisons of Europe how much food will keep the prisoners in athletic condition when exposed to healthy influences. The quantity of food required depends upon the wants of the system and the quality of food consumed. Some articles are far more nutritious than others, and are far less bulky; for instance, the rice eaters of China, the potato and milk consumers of Ireland, eat enormously, compared with the beef-eating people. But rarely will a less quantity than seventeen ounces suffice for the animal economy, and not then, even, unless it is the concentrated essences and principles of carefully selected grains, and healthy meat from cattle killed in their native pastures, like the scientific ration correctly proposed by Professor Horsford. This ration is intended to enable armies to change their base with intervals of more than a month, and to assist raiding parties to perform long journeys without relying for subsistence on the doubtful and difficult forage along the route, or on the distant depots at the point of departure. A handful of the ripe, golden grains, roasted and mixed with a little sugar, with a few ounces of beef dried from the meat of healthy cattle killed instantly, will sustain the power of life wonderfully. This is shown by the mountaineers of the Cordilleras, of the Andes, and the Rocky Mountains. It was substantially the same ration that enabled the Romans to traverse countries far remote from their main depots of supplies, and the Greeks to advance across, with safety, the immense arid deserts of Asia. Any of our splendidly equipped and fed armies of modern times would perish in a few days along the route where Xenophon and his immortal ten thousand passed with safety, and without much loss. IX.