LAZARETTO is the name given to certain building's and enclosures which are annexed to seaport towns, chiefly in the Mediterranean, for the sake of keeping therein confined the crews of ships and passengers arriving from Turkey, or other !dame where the plague, or other di ease deemed contagious, is known to prevail. The persons thus con fined are said to be in quarantine, from the Italian word guars:tete, " forty," because the period of confinement for those arriving from actually infected places is forty +lays, after which, if no one has fallen ill, they are set at liberty. A lazaretto generally consists of various detached buildings with eourta between, the whole surrounded by a wall, and placed in airy situations outside of the town, and on the sea shore, and in some instances on a small island or rock near the coast. Besides the lodging-houses for persons in quarantine, there are large warehouses in which goods capable, or supposed to be capable, of communicating the disease, such as wool, cotton, leather, &c. are purified. This purification is effected by spreading them out in the air for a length of time, and stirring and turning them about, which is done by the "guardhuii," or keepers of the establishment, who, it is supposed, if there were any infection, would speedily take it. These " guardiani" are kept in strict quarantine, but are well paid for the confinement and risk. These establishments are kept under very strict regulations, any infringement of which is visited by severe penalties, amounting in some cases to death. The principal lazarettos were those of Venice, Leghorn, Marseille, Trieste, Genoa, Messina, and Malta. That at Marseille occupied fifty acres, but has been lately taken in to enlarge the town. The name " lazaretto" is derived from St. Lararus, who, in the Roman calendar, is the patron of lepers, and as leprosy was a very common disease in Italy and other parts of Europe during the middle ages, the hospitals in which lepers were confined obtained the name of lazaretto, and the lepers themselves were called lazzari, a word which has perpetuated itself in the lam.
roni, or lowest clam of the inhabitants of Naples, becauso, as some believe, of their dress. which resembles that which was worn at one time by the lepers. Houses for lepers in England were often called law-houses. John Howard wrote ' An Account of the principal laararettoa in Europe,' 4to., 1789, republished in London, 4to., 1791, Frmn this work it appears, that the lazaretto of Venice was the earliest, and that the rules and tariffs of the other lazarates in Europe were copied from it. The health-office in that city, by which the lazaretto is conducted, was instituted by a decree of the senate in 1484, during a time of pestilence.
In most commercial porta at present, the practice is, in case the incoming ship has not a clean bill of health, to place the ship itself in quarantine, that is, to prevent any intercourse with the shore, or with any other vessel, till it is clearly ascertained that there is no infectious disease on board. In England and some other countries, the doubts that have been thrown on the theory of contagion have relaxed the strict observance of these precautions; and lazarettos are falling out of use. [ Q CARANTINC.] LEAD (Pb,1 from the Latin plumhum). This well-known metal has been in use from the very earliest times ; it is frequently mentioned in the books of Moses, and Pliny describes the manufacture of leaden pipes. The alchemists called it &tern ( first, because they thought It the oldest of the seven then known metal)+, and it might therefore be compared to Saturn, who was supposed to bo the father of the gods ; and meow!, from its power of dissolving other metals it was further likened to Saturn, who, according to fabulous history, was in the habit of devouring his own children.
'With a few very rare exteptiona, lead is never found native or in the metallic state. its ores are numerous [Lean, in NAT. HIRT. DIV.), but it is chiefly from that known as bolero, or sulphide of lead, that the metal is obtained. This ore contains from 75 to 83 per cent. of 12s 1, according to its purity.