In the mines of Hungary the workers dine on two slices of black bread and an apple; the Italians are content with a little oil and a handful of maccaroni; the Chinese exist almost entirely on rice, and the Arabs will live for weeks on dried dates. The surprise is not so much that these people exist, but that they are healthy and strong. Travelers again and again have noted that the Turkish porters in Constantinople will carry a burden that two strong Americans can hardly lift, and that coolies can tire a horse in running with the jinrikisha in China or Japan.
Doubtless most of this abstemiousness is due to poverty, since all nationalities soon fall into our ways of eating when they come to these shores, but their sparingness is none the less a proof that much of what we eat is an unnecessary burden to our stomachs. The primary purpose of eating is to sustain life, not to please the palate. We need material to replenish the waste of tissue, material to make blood and bone and flesh, and that is all.
Out of a pound of meat, not more than one tenth is of any value, and the same proportion holds good with many other articles of food. Now, it is evident that if some method existed by which the nutritious elements could be extracted and concentrated, the process of eating would be greatly simplified, and much to our advantage.
The first effort in this line was made thirty years ago in the shape of condensed milk, and the inventor was heartily laughed at. He lived, however, long enough to laugh at other people, and died worth seven millions of dollars. Now the condensing of milk has grown to be a very large industry.
The processes employed are very simple, the fresh milk being put into a great copper tank with a steam jacket. While it is being heated sugar is added, and the mixture is then drawn off into a vacuum tank, where evaporation is produced by heat.
The vacuum tank will hold, perhaps, nine thousand quarts. It has a glass window at the top, through which the operator in charge looks from time to time. He can tell by the appearance of the milk when the time has arrived to shut off the steam, and this must be done at just the right moment, else the batch will be spoiled.