Antoninus Musa cured Caesar Augustus of hypochondriasis by means of this plant.
The most common variety of the wild Lettuce, improved by frequent cultivation, is the Cabbage Lettuce, or Roman, "which is the best to boil, stew, or put into hodge-podge." Different sorts of the Cos Lettuce follow next onwards. The Lactuca sylvatica is a variety of the wild Lettuce producing similar effects. From this a medicinal tincture (H.) is prepared, and an extract from the flowering herb is given in doses of from five to fifteen grains. No attempt was made to cultivate the Lettuce in this country until the fourth year of Elizabeth's reign.
When bleached by gardeners the lettuce becomes tender, sweet, and succulent, being easily digested, even by dyspeptic persons, as to its crisp, leafy parts, but not its hard stalk. It now contains but little nutriment of any sort, but supplies some mineral salts, especially nitre. In the stem there still lingers a small quantity of the sleep-inducing principle, "lactucarin," particularly when the plant is flowering. Galen, when sleepless from [310] advanced age and infirmities, with hard study, took decoction of the Lettuce at night; and Pope says, with reference to our garden sort:—
"If you want rest,
Lettuce, and cowslip wine:—'probatum est.'"
But if Lettuces are taken at supper with this view of promoting sleep, they should be had without any vinegar, which neutralises their soporific qualities. "Sleep," said Sir Thomas Brown, "is so like death that I dare not trust it without my prayers."
Some persons suppose that when artificially blanched the plant is less wholesome than if left to grow naturally in the garden, especially if its ready digestibility by those of sensitive stomachs be correctly attributed to the slightly narcotic principle. It was taken uncooked by the Hebrews with the Paschal lamb.
John Evelyn writes enthusiastically about it in his Book of Sallets: "So harmless is it that it may safely be eaten raw in fevers; it allays heat, bridles choler, extinguishes thirst, excites appetite, kindly nourishes, and, above all, represses vapours, conciliates sleep, and mitigates pain, besides the effect it has upon the morals— temperance and chastity."
"Galen (whose beloved sallet it was) says it breeds the most laudable blood. No marvel, then, that Lettuces were by the ancients called sanoe by way of eminency, and were so highly valued by the great Augustus that, attributing to them his recovery from a dangerous sickness, it is reported he erected a statue and built an altar to this noble plant." Likewise, "Tacitus, spending almost nothing at his frugal table in other dainties, was yet so great a friend to the Lettuce that he used to say of his prodigality in its purchase, Summi se mercari [311] illas sumitus effusione." Probably the Lettuce of Greece was more active than our indigenous, or cultivated plant.
By way of admonition as to care in preparing the Lettuce for table, Dr. King Chambers has said (Diet in Health and Disease), "The consumption of Lettuce by the working man with his tea is an increasing habit worthy of all encouragement. But the said working man must be warned of the importance of washing the material of his meal. This hint is given in view of the frequent occurrence of the large round worm in the labouring population of some agricultural counties, Oxfordshire for instance, where unwashed Lettuce is largely eaten." Young Lettuces may be raised in forty-eight-hours by first steeping the seed in brandy and then sowing it in a hot-house.
The seeds of the garden Lettuce are emollient, and when rubbed up with water make a pleasant emulsion, which contains nothing of the milky, laxative bitterness furnished by the leaves and stalk. This emulsion resembles that of almonds, but is even more cooling, and therefore a better medicine in disorders arising from acrimony and irritation.