Gerarde considered the plant to be “so exceedingly well known to all our English nation” that it needed no description. In his time (circa 1590), it used to be collected on the commons round London, whence it was brought in plenty to the London markets. At the present day pennyroyal has fallen into neglect, and is not named in the British Pharmacopœia of 1867.
Description—The plant has a low, decumbent, branching stem, which in flowering rises to a height of about 6 inches. Its leaves, scarcely an inch in length and often much less, are petiolate, ovate, blunt, crenate at the margin, dotted with oil-glands above and below. The flowers are arranged in a series of dense, globose whorls, extending for a considerable distance up the stem. The whole plant is more or less hairy. It has a strong fragrant odour, less agreeable to most persons than that of peppermint or spearmint. Its taste, well perceived in the distilled water, is highly aromatic.
Chemical Composition—The most important constituent of pennyroyal is the essential oil, known in pharmacy as Oleum Pulegii, to which is due the odour of the plant. It has been examined by Kane,[1781] according to whom it has a sp. gr. of 0·927. Its boiling was found to fluctuate between 183° and 188° C. The formula assigned to it by this chemist is C₁₀H₁₆O. We ascertained that it contains no carvol ([see page 481].)
Production—Pennyroyal is cultivated at Mitcham and is mostly sold dried; occasionally the herb is distilled for essential oil. The oil found in commerce is however chiefly French or German, and far less costly than that produced in England.
Uses—The distilled water of pennyroyal is carminative and antispasmodic, and is used in the same manner as peppermint water.
HERBA THYMI VULGARIS.
Garden Thyme; F. Thym vulgaire; G. Thymiankraut.
Botanical Origin—Thymus vulgaris L., a small, erect, woody shrub reaching 8 to 10 inches in height, gregarious on sterile uncultivated ground in Portugal, Spain, Southern France and Italy, and in the mountainous parts of Greece. On Mont Ventoux near Avignon, it reaches an elevation above the sea of 3700 ft. (Martins). It is commonly cultivated in English kitchens as a sweet herb,[1782] and succeeds as an annual even in Iceland.
History—We are not aware that thyme had any reputation in the antiquity, nor do we know at what period it was first introduced in northern countries. Garden thyme was commonly cultivated in England in the 16th century, and was well figured and described by Gerarde. It is even said to have been formerly grown on a large scale for medicinal use in the neighbourhood of Deal and Sandwich in Kent.[1783] Camphor of Thyme was noticed by Neumann, apothecary to the Court at Berlin in 1725;[1784] it was called Thymol, and carefully examined in 1853 by Lallemand, and recommended instead of phenol (carbolic acid) in 1868 by Bouilhon, apothecary, and Paquet, M. D. of Lille.
Description—The plant produces thin, woody, branching stems, bearing sessile, linear-lanceolate, or ovate-lanceolate leaves. These are about ¼ of an inch long, revolute at the margin, more or less hoary, especially on the under side, and dotted with shining oil-glands. The small purple flowers are borne on round terminal heads, with sometimes a few lower whorls. The entire wild plant has a greyish tint by reason of a short white pubescence, yet as seen in gardens the plant is more luxuriant, greener and far less tomentose. It is extremely fragrant when rubbed, and has a pungent aromatic taste.