DAM′SON. A species of small black plum, much used in the preparation of tarts, &c. Damsons are rather apt to disagree with delicate stomachs, and also to affect the bowels. See Plum.
DAN′CING. The practice of dancing as an amusement or exercise must be almost as old as the human race itself. Yet, notwithstanding its antiquity and prevalence amongst all nations, both barbarous and refined, the propriety and advantages of its cultivation are of a very questionable character. In a hygienic point of view it can claim no preference, as an exercise, over the more simple ones of walking and running; whilst, from the associations it frequently induces, and the heated and confined atmosphere in which its votaries commonly assemble to indulge in it, it becomes the fertile parent of immorality and consumption. A celebrated cyclopædist has, perhaps harshly, but truthfully, defined dancing to be “a silly amusement for the idle and thoughtless.”
DANDELI′ON. Syn. Piss-a-bed; Tarax′acum (Ph. L. E. & D.), L. A common British plant of the natural order Compositæ. It is known among botanists by the names Taraxacum officinale, T. dens leonis, and Leontodon Taraxacum (Linn.). Its root (Taraxaci Radix, B. P.) is employed in medicine, being diuretic and tonic. It is roasted and used as coffee, and when mixed with an equal weight of foreign coffee constitutes the article once so much puffed under the name of ‘dandelion coffee.’ A similar mixture prepared with chocolate forms the ‘dandelion chocolate’ of the shops. The blanched leaves are used in salads, and the inspissated juice, extract, and decoction are employed in medicine, and are considered as detergent, aperitive, and deobstruent. Ground roasted dandelion root cannot now be sold under the name of ‘dandelion coffee’ or mixed with coffee unless it has previously paid the chicory duty. See Decoction, Extract, &c.
DANDRIFF. This is a scaly disease affecting the head, and giving rise to the formation of the small troublesome particles known as scurf. A serviceable application is two drachms of borax dissolved in a pint of camphor water; the head to be washed with this lotion once or twice a week, or much benefit may also be derived by washing the head with tepid water, agitated with a piece of quillar bark until a strong lather is produced; or with water containing salt of tartar, in the proportion of two drachms of the salt to a pint of tepid water. As a general rule, the use of soap is to be discountenanced.
DAN′IELL’S BATTERY. See Voltaic Electricity.
DAPH′NIN. A peculiar bitter principle, discovered by Vauquelin in the Daphne mezereum or mezereon. It is procured by separating the resin from the alcoholic tincture of the bark by evaporation; afterwards, diluting the residue with water, filtering, and adding acetate of lead. A yellow substance falls down, which, when decomposed by sulphuretted hydrogen, yields daphnin, under the form of small, colourless, transparent, radiated needles.
It is bitter; volatile; sparingly soluble in cold water; freely soluble in hot water, and in alcohol and ether. It possesses basic properties. See Mezereon.
DARNEL. The powder of the seed of the Lolium temulentum, a poisonous grass, is not unfrequently found mixed with the flour of wheat, oats, and other cereals, and when these latter, under these circumstances, are partaken of as food, they give rise to more or less alarming symptoms of poisoning, which are thus enumerated by Dr Pareira:—Headache, giddiness, languor, ringing in the ears, confusion of sight, dilated pupil, delirium, heaviness, somnolency, trembling convulsions, paralysis, and great gastro-intestinal irritation. One of the most specific signs of poisoning by darnel seeds is said by Seeger to be the trembling of the whole body. Dr Taylor mentions a case in which thirty persons who had partaken of bread containing darnel seeds were violently attacked with the above symptoms; and another case is on record of sixty persons in a prison at Cologne being similarly attacked from the same cause. Hassall states that the flour of the darnel seed presents the following appearance under the microscope:—“The starch corpuscles are polygonal, and resemble in this respect those of rice. They are, however, much smaller, and frequently united into compound grains of various sizes, the larger grains consisting of some fifty or sixty starch corpuscles.” The structure of the testa is very different from that of either rice or oat, or indeed any of the other cereal grains. It is formed of three coats or membranes. The cells of the outer coat form but a single layer, and, contrary to the arrangement which exists in the oat, their long axes are disposed transversely, in which respect they resemble rice. The fibres of the husk of rice and the cells of the testa of Lolium are, however, very distinct in other respects. In the former the cells are long and narrow, forming fibres, while in the latter they are but two or three times as broad.
The cells of the second coat, which are ranged in two layers, follow a vertical disposition, an arrangement which is contrary to that which obtains in all the other cereal grains with the exception of rice. The cells of the third coat form but a single layer, and resemble those of other grains.