One of the most important of opium substitutes is derived from a plant in itself not only harmless, but extensively used as an article of food: it is _Lactucarium_ or Lettuce Opium, and is prepared generally from the wild lettuce, although similar properties exist to a more limited extent in the cultivated varieties which find their way to our tables. There is no certainty about the period at which lettuce was introduced into this country, although the time has been fixed at 1520, when it is stated to have been brought from Flanders. In the early part of the reign of Henry VIII., when Queen Katherine wished for a salad, she despatched a messenger to Holland or Flanders; at that period, therefore, very few English tables could ever boast the honour of a salad. In the privy purse expenses of Henry VIII., in 1530, an item occurs from which we learn that the gardener of York Place received a reward for bringing “lettuze” and cherries to Hampton Court. This was policy on the part of the King, his royal consort having a liking for salads, for it was rather expensive as well as tedious, to send for them to the gardens of Brabant.[22] In 1600, peas, beans, and lettuce were in common use in England; and in 1652, a writer of the time speaks of lettuce as a plant with which the public generally had been long familiar. One variety of the cultivated lettuce was doubtless derived from the island of Cos, inasmuch as it still bears that name. Lettuces were known to the ancients. Dioscorides and Theophrastus speak of them as cultivated by the Greeks, and also used in medicine; the prickly lettuce is still found wild on the higher hills of Greece, and was probably one of the species to which the above-named ancient authors refer. Several varieties of the garden lettuce were used in salads by both Greeks and Romans. The pride of the garden of Aristoxenus was his lettuces, and he irrigated them with wine. Two species of wild lettuce are found in Britain, the acrid and the prickly lettuce, both of which possess similar properties, yielding a juice from which lactucarium may be prepared. Two other wild species are only occasional. The lactucarium of the London Pharmacopœia is prepared only from the garden lettuce, but the acrid lettuce is stated to yield a much larger quantity and of superior quality. A single plant of the garden lettuce will yield only 17 grains of lactucarium, on an average, while a plant of the acrid lettuce yields no less than 56 grains, or more than three times that quantity; and although the milkiness of the juice increases till the very close of the time of flowering, or till the month of October in this climate, the value of the lactucarium is deteriorated after the middle of the period of flowering, for subsequently, while the juice becomes thicker, a material decrease takes place in the proportion of bitter extract contained in it.