P L A P L A 213 in the latter town on the 22d January 1858. Plattner s father, though only a poor working miner, found the means for having his son educated first at the " Berg- schule " and then at the " Bergakademie " of Freiberg. After having completed his curriculum there in 1820, he obtained a position in connexion with the royal mines and metal works, and was employed chiefly as an assayer, in which capacity he soon became conspicuous by his rare exactness and circumspection, and his constant striving after scientific advancement. The mouth-blowpipe, after doing service for centuries to metal-workers as a soldering tool (hence the German name Lothrohr), in the hands of Gahn and subsequently of Berzelius became the most useful of instruments for the qualitative testing of mineral substances. Through the efforts of the latter, in fact, blowpipe analysis had developed into almost an independent branch of analysis. But nobody dreamt of quantitative mouth-blowpipe assaying until Harkortin 1827 (while a student in the Freiberg academy) succeeded in working out a blowpipe-assay for silver. Harkort stopped there ; but the idea of blowpipe-assaying was taken up subsequently by Plattner, who, by bringing his characteristic thoroughness, indefatigability, and unex ampled dexterity to bear on the subject, succeeded in working out reliable methods for all the ordinary useful metals. His modes of assaying for cobalt and nickel more especially quickly found favour with metallurgists, because they were more exact than the then known corresponding methods of " wet- way " analysis, and required a less number of hours than the latter required of days for their execu tion. Our analytical methods for the determination of cobalt have since become far more perfect but no less troublesome, and to the present day Plattner s nickel-assay is the most precise method for the estimation of this metal in complex mixtures. Plattner, while working at this specialty of his own, at the same time overhauled the entire field of qualitative blowpipe assaying, and ultimately summed up the whole of his vast experience in his Probirkunst mil dem Lothrohr, which soon became, and to the present day ranks as, the standard book on the subject. Since its first publication in 1835 the work has gone through four editions, apart from two independent English translations. With all his high and recognized distinction in his own specialty, Plattner most keenly felt that his scientific education in Freiberg had been somewhat one-sided ; and in 1839 he left his post and family to work for a year in Heinrich Rose s laboratory in Berlin, and supplement his knowledge of modern methods of chemical analysis. While there as a student he at the same time acted as a teacher in his branch, and won the lasting friendship of a number of distinguished scientific men. On his return home in 1840 he was raised to the rank of assessor at the Government board of mining and metallurgy, and made chief of the royal department of assaying. In 1842 he was deputed to complete a course of lectures on metallurgy in the Bergakademie which had been commenced by Lampadius ; and he subsequently became Lampadius s suc cessor as professor of that branch, and for the then newly instituted course of blowpipe-assaying. In addition to these functions he instituted, in 1851, a special course on the metallurgy of iron. He continued lecturing in the academy as long as he was able, until the session of 1856-57. It was during this period of professorial activity that he made the extensive studies and experi mental researches which form the basis of his work Die metallurgischen Kostprocesse theoretisch letrachtet (Freiberg, 1856). His well-known Vorhsungen iiber allgemeine Hiittenkunde (vol. i. and ii., Freiberg, 1860) is a posthumous publication edited by Prof. Thomas Richter. In addition to these great works (and the Probirkunst) Plattner published (in Erdmanris Journal and in Schweig- ger s Journal and elsewhere) numerous memoirs on metal lurgical or mineralogical subjects, regarding which we must confine ourselves to saying that they mark him as an investigator of rare diligence and power. How he found time for all his original work is difficult to say ; it certainly did not cause him to neglect his students. He attended to them in the most conscientious and effi cient manner, as hundreds of his pupils all over the world can testify. His marked success as a teacher was no doubt owing greatly to his high personal qualities, his cheerful, untiring, unselfish devotion to duty, his kind liness of heart and manner, his freedom from all cant and morbid ambition. The latter years of his life were embittered by intense suffering. After a long period of lingering illness he succumbed to a disease of the brain. PLATTSBURGH, a village and township of the United States, the shire-town of Clinton county, New York, and the port of entry of Champlain customs district, Jies on the west side of Lake Champlain at the mouth of the Saranac. By rail it is 168 miles north of Albany and 73 south-south-east of Montreal (Canada). A branch line runs 20 miles south-west to Au Sable and forms a favourite route to the Adirondacks, and the Chateaugay Railroad runs 34 miles west by north to Lyon Mountain, where there are extensive iron mines. Plattsburgh contains county build ings and court-house, a custom-house, a high school, and a small public library. It has nail and .waggon factories, flour-mills, saw-mills, an iron furnace, machine shops, and a large sewing-machine manufactory. It is a garrison town of the United States army, with extensive barracks about a mile south of the village. The value of the imports and exports of the district for the year ending June 30th 1884 was $3,169,780 and $1,319,422 ; and 1279 vessels entered from Canada, while 1179 cleared. The aggregate burthen of the vessels belonging to the district was 57,477 tons. In 1870 the township had 8414 inhabitants, the village 5139 ; in 1880 the figures were 8283 and 5245. Plattsburgh dates from 1785. It lias twice been destroyed by fire (1849 and 1867). In 1812 it became the headquarters of the U.S. army on the northern frontier; and in September 1814 it was rendered famous through the capture of the British flotilla under Commodore Downie by the United States flotilla under Commodore Macdonough, and the consequent retreat across the Saranac of Sir George Prevost, who had been attacking the village with a powerful army. Downie and fifteen other officers of the contending forces arc buried in Plattsburgh cemetery. PLATYHELMINTHES. See PLANARIAXS and TAPE- WOEMS. PLATYPUS. The Duck-billed Platypus (Platypus anatinus) was the name assigned to one of the most remarkable of known animals by Shaw, who had the good fortune to introduce it to the notice of the scientific world in the Naturalist s Miscellany (vol. x., 1799) In the fol lowing year it was independently described by Blumenbach ( Voigts Magazin, ii. p. 205) under the name of Ornitko- rhynchus paradoxus. Shaw s generic name, although having priority to that of Blumenbach, could not be retained, as it had been used at a still earlier time (1793) by Herbst for a genus of Coleoptera. Ornithorhynchus is therefore now universally adopted as the scientific designa tion, although Duck-billed Platypus may be conveniently retained as a vernacular appellation By the colonists it is called "Water-Mole," but its affinities with the true moles are of the slightest and most superficial description. The anatomical differences by which the platypus, and its only ally the echidna, are separated from all other mammals, so as to form a distinct subclass with relation ship to the inferior vertebratecl classes, have been described
in the article MAMMALIA (vol. xv. pp. 371 and 377), where