This section is from the book "Meals Medicinal", by W. T. Fernie. Also available from Amazon: Meals Medicinal: With "Herbal Simples" Curative Foods From the Cook in Place of Drugs From the Chemist.
Our garden Lettuce is a cultivated variety of the wild, or strongly scented Lettuce (Lactuca virosa) which grows with prickly leaves on banks and waysides in chalky districts throughout England and Wales. This wild Lettuce contains the medicinal properties of the plant more actively than does the garden Lettuce, as grown for kitchen uses. Chemically, the cultivated Lettuce which comes to our tables contains in quite a modified degree principles which in the wild plant are narcotic, and dangerous. But these principles, lactucin, lactuccpicrin, and asparagin, with oxalic, malic and citric acids, mannite, albumin, gum, and resin, have become as completely toned down, and rendered harmless, as were the child-like manners, and the pensive smile of Bret Harte's Heathen Chinee. The Lettuce, or milk plant, was esteemed by the early Romans as a sedative for inducing sleep, and to be eaten after a debauch of wine. They prepared this vegetable with eggs, and served it with the last course at their meals, so as to stimulate the appetite afresh. With ourselves, the Roman, or Cabbage Lettuce, is the best to "boil, stew, or put into hodge-podge "; then come different sorts of the Cos Lettuce to be eaten raw.
When tied up compactly, and thus bleached as to its inner leaves, the lettuce remains tender, crisp, and succulent, being easily digested, even by dyspeptic persons, except as regards the hard stalk. The lettuce contains but little nutriment, though supplying some mineral salts, particularly nitre. In the stem there still lingers a small amount of the sleep-inducing principle, lactucerin, especially when the plant is flowering. The Cabbage Lettuce, lactuca sativa vericeps, is slightly bitter, because of its milky juice containing the soothing principle lactucin. Galen termed the plant "philosopher's, or wise man's herb." Its condensed juice is named thridax in France, and lactucarium in England, when drying into a kind of gum, brown like the opium-gum of Poppies, but much milder of effects. Two grains of this lactucarium from the garden lettuce may be safely given to a young child for soothing it to sleep. Mr. Roker, the rough turnkey of the Fleet Prison in which Mr. Pickwick chose to be incarcerated for debt, on being asked to point out which was the bedstead allotted to that gentleman, denoted a very rusty one in the corner of the room. "It would make one go to sleep, that bedstead would," said Roker, "whether they wanted to, or not." "I should think," said Sam Weller, (Mr. Pickwick's manservant), eying the piece of furniture in question, with a look of excessive disgust, "I should think poppies was nothing to it".
With regard to peace of mind as essential towards good sleep, "beware," says Dr. Kennedy, "of the theologians who have no sense of mirth; they are not altogether human. Keep your chin up, don't take your troubles to bed with you, hang them on a chair with your trowsers, or drop them into a glass with your teeth." Pope has sung concerning our garden lettuce:
"If you need rest. Lettuce, and cowslip wine, - probatum est".
But if the lettuce is taken at supper with the view of promoting sleep, it should be had without any vinegar, which would neutralize its soporific effects. In his Book of Sallets John Evelyn writes enthusiastically about the Lettuce, "So harmless is it that it may be safely 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 charity." "By reason," concludes Evelyn, "of its soporiferous quality, the Lettuce ever was, and still continues to be the principal foundation of the universal tribe of sallets, because it cools and refreshes, besides its other properties, and therefore was held in such high esteem by the ancients that divers of the Valerian family dignified and ennobled their name with that of Lactucinii. It is botanically distinguished as the Lactuca sattva, from the plenty of milk that it hath, and causeth".
"Lettuce of lac derivyed is perchaunce, For mylk it hath, or yeveth abundaunce".
"With the old Romans" (vegetable feeders) adds Evelyn, "time was before men, in those golden days" (and less sleep was needed than now), "their spirits were brisk, and lively ":
"Ubi dicto citius curata sopori Membra dedit; vegetus praescripta ad munera surgit".
"With shorter, but much sweeter sleep content Vigorous, and fresh about their business went".
"They could then make an honest meal, and dine upon a sallet, without so much as a grain of exotic spice".
"See now how pale they look, how wretchedly With yesterday's surcharge disturbed they be; Nor body only suff'ring, but the mind, That nobler part, - dull, and depress'd we find".
Lettuce, after wine, says Horace, swims in the soured stomach:
"Nam lactuca innatat acri Post vinum stomacho".
That excellent Emperor, Tacitus, used to say of Lettuce that he did "summum se mercari," when he ate of them, and call'd it a sumptuous feast, with a sallet, and a single pullet; which was usually all the flesh-meat that sober prince ate of; whilst Maximinus (a professed enemy to salad), is reported to have "scarce been satisfy'd with sixty pounds of flesh, and drink proportionable." Boiled Lettuce (in its own water only) has a very delicate flavour, being considered by some persons superior even to asparagus. Take a large, well-grown Lettuce, and wash it thoroughly in strong salt and water to remove insects, then rinse it well out in fresh water, and gently stew it for ten or fifteen minutes. Serve on buttered toast, with a light sprinkling of pepper and salt. Sorrel soup (bonne femme) is to be made also with Lettuces. Leaves of Cabbage Lettuces are bruised with the sorrel in butter, treated with bouillon, and a liaison of egg-yolk, butter, sugar, and browned gelatinous gravy. The sorrel and lettuce must be present in about equal quantities; less than this of sorrel would be useless.