I have gone more fully into this part of my subject than I intended, for the following reason: the advocates of total abstention from salt invariably bring forward scurvy as a conclusive proof of their argument, and as unanswerable; they have not looked at it, I am afraid, from the above standpoint, and I think if they will take the trouble to go into the matter more thoroughly, they will find that scurvy originates, not from wholesome salted provisions and the want of vegetables, but from impure and putrid food, which too many owners of ships, from pecuniary motives, prefer to supply, not for the passengers—that would of course be unwise policy—but for the men who labour for them on the waters, and who are at the mercy of employers as insatiable and inexorable in obtaining their pounds of flesh as the storm-tossed ocean yawning for its victims.
“Digestion is the process by which those parts of our food which may be employed in the formation and repair of the tissues, or in the production of heat, are made fit to be absorbed and added to the blood.”
I do not think it will be out of place to make a few cursory observations on the process of digestion, for as scurvy is the result of the ingestion of unwholesome food, we cannot do better than consider the process in relation to salt, and its action on animal and vegetable food while it is in the stomach.
When this organ is empty it is completely inactive; there is no secretion of the gastric juice, and the mucus, which is slightly alkaline or neutral, covers the surface; but immediately food is introduced, the mucous membrane, which was pale, at once becomes turgid, owing to the greater influx of blood; because when any organ has work to perform, it requires an increased supply.
The amount of the gastric juice secreted has been variously estimated to be from ten to twenty pints a day in a healthy adult, and by the following table, we find that salt, or rather the chloride of sodium, is present in a considerable quantity. Looking, then, at the immense secretion of the gastric juice, salt is really in continual requisition, making it self-evident that if the supply is not kept up in the same ratio, digestion is retarded, the food passes out of the stomach in an undigested state into the duodenum, and the stomach is consequently overstrained because of the loss of one of its most important constituents; the supply of salt not being equal to the demand.
Composition of Gastric Juice.
| Water | 994·40 |
| Solid Constituents | 5·59 |
| ——— | |
| Ferment, Pepsine (with a trace of Ammonia) | 3·19 |
| Hydrochloric Acid | 0·20 |
| Chloride of Calcium | 0·06 |
| Chloride of Sodium | 1·46 |
| Chloride of Potassium | 0·55 |
| Phosphate of Lime, Magnesia, and Iron | 0·12 |
In a sheep’s gastric juice there is to 971·17 of water, 4·36 of chloride of sodium, showing at once how highly necessary it is for cattle to be supplied with it; a sheep will consume on the average half an ounce of salt daily; that it tends to prevent an outbreak of the rot, I have already drawn the attention of the reader.[54]
There is we see 0.20 of hydrochloric acid to 994.40 of water in the gastric juice, though some are of an opinion that it is lactic acid; the weight of evidence is decidedly in favour of free hydrochloric acid.
Food when it is going through the process of digestion is reduced to a pulp by the solvent properties of the gastric juice, which are due to the presence of the animal matter or pepsine, and the hydrochloric acid; neither of these two constituents can digest separately, they must be together; and they must be in that proportion as we have before us in the preceding table; to act as complete disintegrators and solvents.