PILOCARPINE  , C„H,6N2O2, an

alkaloid found, together with isopilocarpine and other related compounds, in the leaves of jaborandi (Pilocorpus pennatifolius) . It was first isolated by E . Hardy in 1875 (Ber., 8, p . 1594), and is a crystalline, very hygroscopic solid . It is a strong poison . It has the properties of a monacid base and contains the methylamino group, .NCH3 . When heated with hydrochloric acid it gives isopilocarpine . Isopilocarpine was isolated in 1900 by H . A . D . Jowett (Journ . Chem .

Soc . 77, p . 473), and is a colourless oil which boils at 261° C . (to mm.) . It is a monacid base which is readily soluble in solutions of the caustic alkalis . Jowett is of the opinion that pilocarpine and isopilocarpine are stereo-isomers of the structure:— /CH•N•CH3CzH5•CH•C0\ Nl O \CH: C—CHz—CH•CH/z latter kind is the only one to which the term is now applied either in British or foreign countries . The word " pilot " is not the early name for the man who guides or steers a ship .. In Old English the name is lfidman, i.e. the man who leads the way . " Pilot " does not appear in English till the 16th century . The origin of the word has been much debated . Many etymologists find it in the Dutch pijloot (Hexham's Dictionary, 1658) . This has been identified with peillood, peil-loth, sounding lead, cf .

German peilen, to sound; the last part of these words is the same as English " lead," the metal; the first part, peilen, is for pegelen, to mark with pegs or points for measuring, cf. pegel, gauge . The New English Dictionary, on the other hand, finds that the Dutch pilott, the earlier form, is taken from the French . The source is, therefore, to be looked for in Romance languages . Du Cange (Gloss . Med. et Inf . Lat.) gives Pedottae, defined as quorum est scire intrare et exire portus, a gloss on pedotte e timonieri in F . Ubaldini's edition, 164o, of I documenti d'amore by Francesco da Barberino (1264-1348) . It is therefore conjectured that the Italian pilota is a popular conception of pedal/a, and a possible source may be found in the Greek 765ov, oar . In England, formerly, pilots were subject to the jurisdiction of the lord high admiral; and in the 16th century there are many instances of the admiralty court dealing with pilots disciplinarily as well as civilly, holding them liable in damages to owners of ships lost or damaged by their negligence . For some consider-able time throughout the United Kingdom the appointment and control of pilots have been in the hands of numerous societies or corporations established at the various ports by charter or act of Parliament, such as the Trinity Houses of Deptford Strond (London), Kingston-upon-Hull, Newcastle-on-Tyne, and Leith, and the Society of Cinque Ports Pilots and Court of Lodemanage (now extinct) . These societies had jurisdiction over the pilots exercising their employment within Authorities> the limits of such ports, and in many cases made it compulsory for ships resorting thither to employ them . By degrees the London Trinity House acquired a leading position, which was confirmed and extended by the general Pilotage Acts passed in the 18th and 19th centuries, with the object of introducing a uniform system throughout the realm .

At the

present day the United Kingdom is divided into districts for the purpose of ,pilotage jurisdiction . The (London) Trinity House has jurisdiction over the London district, which extends from Orfordness to Dungeness, and comprises the Thames and Medway up to London and Rochester bridges; the English Channel district, comprising the sea between Dungeness and the Isle of Wight; , and the Trinity outport districts, which include any pilotage districts for the appointment of pilots within which no particular provision is made by act of Parliament or charter, and the number of which is 40, all English and Welsh . There are 66 other districts, within which other pilotage authorities have jurisdiction . The present general pilotage law is contained in the Merchant Shipping Acts 1894 to 1906 . Pilotage authorities are defined as bodies or persons authorized to appoint or license pilots, or to fix and alter rates of pilotage or to exercise any jurisdiction in respect of pilotage . They are subject to the control of the Board of Trade as the supreme mercantile marine authority . Those bodies, however, which existed at the time of the passing of the act retain their powers and jurisdiction, so far as is consistent with it . The board has power to appoint a new pilotage authority in any area where there is none, and to include a new area where there is none within an already existing one (but in either case pilotage cannot be made compulsory), or to transfer pilotage jurisdiction over a port other than that where the pilotage authority for that port resides, from that pilotage authority to the harbour or other local authority for that port, or to the Trinity House, or to a new authority; and the board has all powers necessary to effectuate such transfer and constitute the new authority .