The Latin name Nasturtium was given to the Watercress because of its volatile pungency when bruised and smelt; from nasus, a nose, and tortus, turned away, it being so to say, "a herb that wriths or twists the nose." For the same reason it is called Nasitord in France. When bruised its leaves affect the eyes and nose almost like mustard. They have been usefully applied to the scald head and tetters of children. In New Zealand the stems grow as thick as a man's wrist, and nearly choke some of the rivers. Like an oyster, the Water-cress is in proper season only when there is an "r" in the month.
According to an analysis made recently in the School of Pharmacy at Paris, the Water-cress contains a sulpho-nitrogenous oil, iodine, iron, phosphates, potash, certain other earthy salts, a bitter extract, and water. Its volatile oil which is rich in nitrogen and sulphur (problematical) is the sulpho-cyanide of allyl. Anyhow [130] there is much sulphur possessed by the whole plant in one form or another, together with a considerable quantity of mineral matter. Thus the popular plant is so constituted as to be particularly curative of scrofulous affections, especially in the spring time, when the bodily humours are on the ferment. Dr. King Chambers writes (Diet in Health and Disease), "I feel sure that the infertility, pallor, fetid breath, and bad teeth which characterise some of our town populations are to a great extent due to their inability to get fresh anti-scorbutic vegetables as articles of diet: therefore I regard the Water-cress seller as one of the saviours of her country." Culpeper said pithily long ago: "They that will live in health may eat Water-cress if they please; and if they won't, I cannot help it."
The scrofula to which the Water-cress and its allied plants are antidotal, got its name from scrofa, "a burrowing pig," signifying the radical destruction of important glands in the body by this undermining constitutional disease. Possibly the quaint lines which nurses have long been given to repeat for the amusement of babies while fondling their infantine fingers bear a hidden meaning which pointedly imports the scrofulous taint. This nursery distich, as we remember, personates the fingers one by one as five little fabulous pigs:—the first small piggy doesn't feel well; and the second one threatens the doctor to tell; the third little pig has to linger at home; and the fourth small porker of meat has none; then the fifth little pig, with a querulous note, cries "weak, weak, weak" from its poor little throat.
"oegrotat multis doloribus porculus ille:
Ille rogat fratri medicum proferre salutem:
Debilis ille domi mansit vetitus abire;
Carnem digessit nunquam miser porculus ille;
'Eheu!' ter repetens, 'eheu!' perporculus, 'eheu!'
Vires exiguas luget plorante susurro."
[131] On account of its medicinal constituents the herb has been deservedly extolled as a specific remedy for tubercular consumption of the lungs. Haller says: "We have seen patients in deep declines cured by living almost entirely on this plant;" and it forms the chief ingredient of the _Sirop Antiscorbutique _given so successfully by the French faculty in scrofula and other allied diseases. Its active principles are at their best when the plant is in flower; and the amount of essential oil increases according to the quantity of sunlight which the leaves obtain, the proportion of iron being determined according to the quality of the water, and the measure of phosphates by the supply of dressing afforded. The leaves remain green when grown in the shade, but become of a purple brown because of their iron when exposed to the sun. The expressed juice, which contains the peculiar taste and pungency of the herb, may be taken in doses of from one to two fluid ounces at each of the three principal meals, and it should always be had fresh. When combined with the juice of Scurvy grass and of Seville oranges it makes the popular antiscorbutic medicine known as "Spring juices."
A Water-cress cataplasm applied cold in a single layer, and with a pinch of salt sprinkled thereupon makes a most useful poultice to heal foul scrofulous ulcers; and will also help to resolve glandular swellings.
Water-cresses squeezed and laid against warts were said by the Saxon leeches to work a certain cure on these excrescences. In France the Water-cress is dipped in oil and vinegar to be eaten at table with chicken or a steak. The Englishman takes it at his morning or evening meal, with bread and butter, or at dinner in a salad. It loses some of its pungent flavour and of its curative qualities [132] when cultivated; and therefore it is more appetising and useful when freshly gathered from natural streams. But these streams ought to be free from contamination by sewage matter, or any drainage which might convey the germs of fever, or other blood poison: for, as we are admonished, the Water-cress plant acts as a brush in impure running brooks to detain around its stalks and leaves any dirty disease-bringing flocculi.
Some of our leading druggists now make for medicinal use a liquid extract of the Nasturtium officinale, and a spirituous juice (or succus) of the plant. These preparations are of marked service in scorbutic cases, where weakness exists without wasting, and often with spongy gums, or some skin eruption. They are best when taken with lemon juice.
The leaf of the unwholesome Water parsnep, or Fool's Cress, resembles that of the Water-cress, and grows near it not infrequently: but the leaves of the true Water-cress never embrace the stem of the plant as do the leaf stalks of its injurious imitators. Herrick the joyous poet of "dull Devonshire" dearly loved the Water-cress, and its kindred herbs. He piously and pleasantly made them the subject of a quaint grace before meat:—
"Lord, I confess too when I dine
The pulse is Thine:
And all those other bits that be
There placed by Thee:
The wurts, the perslane, and the mess
of Water-cress."