CHAPTER VI.
THE HUMAN ENGINE AND HOW TO STOKE IT.
An express train was standing in a London terminus, on the point of starting for her run to Edinburgh. Several persons were admiring the great locomotive, which was throbbing like a hound in leash, ready to be off the moment the guard’s signal was given. The guard waved his flag, and the train glided out of the station so smoothly, that the unwary passenger standing up in his compartment at the time was not even jolted. The first stopping-place, a hundred miles away, was reached on the stroke of time, without a hitch of any sort.
The man who was responsible for this perfect running was not the driver so much as the stoker, that humble individual, as we are apt to regard him, whose duty it was to put the coal on the fires. Unless he had done his work efficiently, the best driver of the finest locomotive ever built could not have made a good run.
He took care to use the right sort of coal, to put in enough of it to keep the fires bright, but not so much as to choke them up, and to shovel it in with discretion and at suitable times. Few people realise that there is a distinct art in stoking a furnace.
Yet that stoker was not a happy man. He was sallow and of a livery type. He often suffered from headaches and spots before his eyes, heartburn and nausea. Although he was muscular and powerfully built, he frequently felt so tired and listless that he was hardly able to face his day’s work.
All this was due to the circumstance that, although he had mastered the stoking of an engine, he had never learned to feed himself properly. He had not realised that he himself was an engine, quite as much so as the locomotive he worked on, and that the food he took was the fuel which supplied the driving power to his system and kept his machinery running. It had never dawned on him that there is an art in eating just as important as that of stoking, and demanding as much care and foresight.
He would take his meals at any time that happened to be convenient, and would eat anything that came before him, regardless as to whether it suited him or not. Furthermore, he often ate to repletion, and bolted his food down without masticating it properly. And that was why his own machinery ran badly and he felt tired and depressed. In which respects he was exactly like thousands of other people.
This resemblance between a steam engine and the human body is a pronounced one. As we have already pointed out, the food, after being digested and absorbed through the walls of the digestive tract, is burnt up in the tissues by a process closely corresponding to that of ordinary combustion, and there is a residue of waste products left behind resembling the cinders and ashes of a coal fire. Nature is able in various ways to dispose of this waste, eliminating it from the body. If, however, the amount of food taken be excessive, the residue is so large that the resources of the system are not sufficient to cope with it, and in consequence it accumulates in the tissues.
Then the individual suffers from discomfort or pains in the muscles, and from headache with a sense of tiredness, even apart from exercise or work; also from various other symptoms, owing to this waste matter circulating in the blood.
The wrong sort of food may have been taken, or eaten either too quickly or at unsuitable times, and dyspepsia results. Then there is a certain amount of undigested food constantly left behind in the stomach, and this begins to ferment, developing a poison of its own, which gets into the circulation and aggravates the effect of that already present. At the same time the nutritive quality of the food is diminished, so that there is superadded a process of starvation. There is plenty of food, but little nourishment.