BLACK DEATH. 139 BLACK FLY. them. In ■some places, the .Jewish people im- molated themselves in masses : in others, not a soul of them survived the assaults of their ene- mies. Xo adequate notion ean be conveyed of these horrors. To aggravate the pestilence, the poison-panic made the people shut up tlieir wells. Vith terror of poison and of plague in a state of society rude at the best, but now disorgan- ized, what means were available to mitigate or ]>revent tlie siill'erings of the people were rendered altogether nugatory. The enormous decrease in the p(i|)ulation of Europe occasioned by the Black Death necessarily brought about gicat and last- ing changes in social conditions. Perhaps on no class of society were the etTects of the jilague so marked as on the laboring population, among whom the rate of mortality had been especially great. Immediately after the cessation of the pestilence, what would be called at present a very serious stringency in the labor market ensued. In England, where probably one-half of the pop- ulation had been swept away (according to some chroniclers the survivors numbered only one- tenth), the agricultural laborers banded together for the purpose of securing higher wages. This led to a struggle between the laborers and the landlords, which took the form of violence on one side, and on the other of legislation fixing the scale of wages and prohibiting the migration of laborers from place to place, culminating in the peasant revolt of 1381 (see Tyleb, Wat), and resulting in the gradual abolition of villeinage anil the reorganization of land-holding relations on the basis of rent, as between owner and ten- ant, and «ages, as between farmer and laborer. BiRLlOGRAPUY. The following authors refer to or describe the Great Plague : Chaucer ; Langland: Boccaccio in the Decameron; Bul- wer. in Rienzi (Boston, 189G) ; Hecker, Epidem- ics of the Middle Ages (London, 1849) : (Treigh- ton, History of Epidemics in Britain (XewYork, 1892) : Hecker, The Black Death (London, 1890) : F. A. Gasquet. The Great Pestilence (London. 1894). See PLAGfE. BLACK DICK. A name applied to AdmiraJ Richard Howe. BLACK DOMINO, The. An English comic opera, adajitcd in 1841 from the French of Scribe's l.c domino noir (Paris, 1837). BLACK DOSE, or DRAUGHT. See Senna. BLACK DOUGLAS, diVliis, The. An ap- pellation of several of the Douglas family of ■Scotland, notably of William, Lord of Nithsdale, who died in 1390, and of the Earl Archibald, who plays a prominent part in Scott's novel The Fair Mil id of I'rrth. BLACK DUCK, BEAR, SQUIRREL, TERN, etc. S<-e the substantives. BLACK DWARF, The. The title of a novel by Scott (ISltj). Its scene is laid in the time of . ne, and it is foimded on a Scottish legend concerning a. malignant creature who is thought to l)c the cau.se of all mischances to cattle and sheep. In the story, the 'black dwarf is Sir Ed- ward Mauley, a deformed recluse. He forbids the forced marriage of Isabella Vere to Sir Frederick I-angley. and secures her hand for sturdy Patrick Eamsclifr. BLACK EAGLE. See Eagle, Black. BLACK-EYED SUSAN. A sea-song, writ- ten by .lohn Gay in 1720 and set to music by Levcridge. Vol.. III.— 10 BLACK -EYED SUSAN, or All I.n tub DowN.s. The name of a popular comedy of 1829, by Douglas Jerrold, founded on Gay's ballad. BLACKFIN, or Bluefin. A large whitefish (Argyrusomus nigripinnis) of the deep waters of Lake Michigan, distinguished by its blue-black fins. See Plate of Whitefish, etc. BLACKFISH. Any one of a variety of dark- colorcil tislies. Tn the United States the name refers mostly to the tautog (see Tautog and Col- ored Plate with Ftsh as Food. Others are a sea- bass (Crnfropristis striatiis) of the East Coast, and a minnow (Orthodon microlcpidotus) of the Pacific Coast. In Alaska the local Tjlackfish' is a small fresh- water fish {Dallia pecioralis) , set apart as the sole representative of the family Dalliida- and the order Xenomi, which is only 8 inches long. It inhabits the streams and ponds of northern Alaska and Siberia, and abounds in countless numbers in all the ponds and pieces of shallow water, forming the chief food of the natives. "The species feeds on plants and worms. Its vitality is extraordinary. Blackfishes will re- main frozen in baskets for weeks, and when thawed out are as lively as ever." Its body is oblong, color nearly black, and its structure im- ])lies an ancient type. See Plate of Killifishes, etc. In England the name is given to one of the ruffs, a scombroid {Centrolophus niger) , about two feet long, having somewhat the shape of a perch, with a single long, rather low dorsal fin. It is good to eat, and occurs rather abundantly in the deeper waters off the south coast of Europe. BLACKFISH. A black killer-whale of the genus Globicephalus. Several species inhabit northern seas. One of these is the bottU?-head, ca'ing, or pilot whale (Globicephalus 7nclas) of British waters. The common blackfish of the Atlantic is Globicephalus brachypicrus, and that of the Xorth Pacific Globicephalus Scummoni. They roam about in herds, like grampuses, and often enter harbors in pursuit of fishes. They are killed for the sake of a small yield of oil resembling sperm-oil, but inferior; the flesh is edible. (See Killeb.) The name is also given by sailors to various other small cetaceans. Con- sult: Bullen, Voyage of the Cachalot (New York, 1898) ; Scammon, Marine Mammals of North- irestern North America (San Francisco, 1874) ; Goode, Fishery Industries, Sec. I. (Washingt<m, 1884) ; True, "Review of the DelphinidiP," in Bulletin V. 8. Nat. Mus., No. S6 (Washington, 1889). BLACK FLUX (Lat. fluxus, a flowing, flow, from jluerc, to How). A mixture of potassium carbonate and charcoal, used as a reducing agent in assaying. It is prepared by mixing one part of potassium nitrate (nitre) with from two to three parts of potassium bitartrate (cream of tartar) and deflagrating by stirring with a red- hot iron until action ceases. The product is pow- dered and kept in a clo.sely covered jar in order to prevent it from absorbing moisture from the atmosphere. An excellent .sjibstitute for ordinary black tlux may be obtained by mixing three parts of flour with ten parts of sodium bicarbonate. BLACK FLY. A gnat of the forest regions of north temperate latitudes, especially torment- ing to man and beast, and representing the fam-
