POTASH. 



241 



ga-re a great impetus to postal progress. Thirty-one 

 articles of agreement were formally adopted, covering 

 all the propositions made by the United States, except 

 that relating to a money-order system, and establishing 

 principles that are still the basis of all international 

 p<>.-tal business. The agreement, however, not being 

 of the nature of a formally ratified convention, did not 

 secure a perfect union, did not establish for it a fixed 

 duration, made no arrangements for future congresses, 

 and tailed to provide for the adhesion of other nations. 

 The necessity for another congress, therefore, in a lew 

 years became manifest; and accordingly, by general 

 consent of the nations represented in the first congress, 

 a second one assembled at Berne, Switzerland, Sept. 

 15, 1*74, and on Oct. 9 agreed to a formal convention, 

 in which the defects of the former agreement were 

 remedied, new provisions adopted, and a name the 

 "General Postal Union" given to the association. 

 The duration of the convention was to be not less than 

 three years from July 1, 1875, and the territory to 

 which it applied comprised the United Slates and the 

 whole of Europe, Asiatic Turkey, Asiatic Russia, 

 Egypt, Iceland and the Faroe Islands as a part of Den- 

 mark, the Balearic Islands, the Canaries, the Spanish 

 possessions on the northern coast of Africa and the 

 Spanish postal establishments on the west coast of 

 Morocco as a part of Spain, Algeria as a part of 

 France, Malta as a part of Great Britain, and Madeira 

 and the Azores as a part of Portugal. On May 1, 

 1878, a third congress assembled at Paris, for the 

 purpose of revising and improving the system estab- 

 lished by the congress of Berne, and continued in 

 session until the 4th of the next month, when a new 

 convention was agreed upon, which was to go into 

 effect April 1, 1879, and was to endure for an indefinite 

 period. By this convention the name of the associa- 

 tion was changed to the " Universal Postal Union" 

 by which name it is still known and the extent of 

 its jurisdiction was greatly enlarged. On Feb. 4. !*>.">, 

 the fourth postal congress met at Lisbon, and adopted 

 a new convention, which went into effect on April 1, 

 188fi, and which is now in force. The next congress 

 will assemble at Vienna in 1890, unless an earlier ses- 

 sion is found to be necessary. 



The scope and aim of the Universal Postal Union 

 are vast and noble, and its work admirably executed 

 It makes a single postal territory of nearly the whol<: 

 world, uniting all nations under a common idea, sub- 

 jecting them to the saiuo laws, establishing them all 

 upon a footing of perfect equality, and making the 

 self-interest of each give way before the interest of 

 all. In a word, ita conspicuous purpose is the good 

 of mankind. The subjects covered by the Convention 

 of the Postal Union are the classification of mail mat- 

 ter, the rates of postage, the transit of matter between 

 the several countries of the Union, direct and through 

 intermediaries, the charges to be made for such inter- 

 MC'li.iry transit and the manner of their settlement, 

 the reforwarding and return of mail matter, the reg- 

 istration of mutter and the charges therefor, & system 

 of indemnifying the owners of mail matter that may 

 be lost, the collection of unpaid postage, and a system 

 for the transmission of letters of declared values. 

 Under it an International Bureau is maintained at 

 Borne, in the Republic of Switzerland, through which, 

 un ler established rules, oorranxwdenoe is carried on 

 between the several countries of the Union, relative to 

 ita general business, to the settlement of disagreements 

 between two or more countries, to the tabulation and 

 publication of statistics, to the admission of new mem- 

 bers to the Union, to proposed changes during the in- 

 tervals between the congresses, and to all other mat- 

 ters that may be of interest or benefit to the postal 

 world. The rates of international pontage as now fixed 

 by the convention are as follows : Letters, 5 cents a 

 half ounce if prepaid, and dunblu this rate (to be col- 

 leetc<l on delivery of the matter) if not prepaid. 

 Postal cards, 2 cents each. Printed matter, commercial 



papers, and samples of merchandise, 1 cent for each 

 ;wp ounces if prepaid, and double this rate if not pre- 

 paid. 



The Postal Union now comprises the following- 

 named countries : The Argentine Republic, Austria- 

 Hungary, Belgium, Bolivia, Brazil, British India, 

 Bulgaria, Canada, Chili, Colombia, the Independent 

 State of Congo, Costa Rica, Denmark and Danish 

 colonies, Dominican Republic, Ecuador, Egypt, Franca 

 and French colonies, Germany, Great Britain and 

 British colonies (except the Australian and other 

 Oceanian colonies). Greece, Guatemala, Hayti, Ha- 

 waiian Islands, Honduras, Italy, Japan, Liberia, 

 Luxembourg, Mexico, Montenegro, Netherlands and 

 Netherlands colonies, Nicaragua, Norway, Paraguay, 

 Persia, Peru, Portugal and Portuguese colonies, Rou- 

 niania, Russia, Salvador, Servia, Siam, South-west 

 Africa, Spain and Spanish colonies, Sweden, Switzer- 

 land, Tunis, Turkey, Uruguay, and Venezuela. 



For further information concerning the Postal Union, see 

 Re|x>rts of Postmaster-General of the United States for 1862, 

 1863, 1874, 1875, 1878, and 1885; also the files of L' Union, 

 Potilnle, the official organ of the International Bureau at 

 Berne, and Document* du Congrtt Postal de Luboiine 

 (Berne, 1885), and to similar documents of the Congresses 

 of Paris and Berne, published iu 1874 and 1878. (M. D.) 



POTASH. The hydrated oxide of potassium, or 

 .... caustic potash (KjOH.0, or, as given 



80S < til)-' by many chemists < KHO), was not 

 Am Rep ) !* nown ** a separate substance till 1739, 

 in which year its distinction from soda, 

 which it resembles in general properties, was first rec- 

 ognized. In its pure state it is mie of the most power- 

 ful basic substances known, andls largely employed in 

 the decomposition of saline substances, whose acid 

 combines with the potash. As existing in nature it is 

 of the utmost importance to the growth of plants. It 

 is prepared from the carbonate by boiling with lime, 

 which seizes the carbonic acid and leaves the hydrate 

 in solution. Its most important sources are the potash 

 minerals, carncllite and sylaite, which exist abundantly 

 in the salt mines of Stassfurt, Germany. In a single 

 locality in these mines there is a mass of carncllite 

 equivalent to G,(XX),OUO tons of chlorate of potassium. 

 Ordinary commercial potash consists of the crude car- 

 bonate and hydrate, and is chiefly obtained from wood- 

 ashes, which contain it in abundance. The method 

 pursued in America is to burn largo heaps of wood to 

 ashes. These are then placed in tubs made from bar- 

 rels sawn in half, and with perforated false bottoms. 

 About 5 per cent, of lime is added, and the ashes are 

 leached by successive applications of water, each of 

 which is allowed to stand for an hour or two. The 

 water is then drawn off from the bottom, the first 

 draining being taken to the evaporating pans, while 

 the succeeding portions are kept to use on fresh ashes. 

 Broad, shallow iron pans are used in which the liquid 

 is boiled till it becomes syrupy. It grows solid on 

 cooling. The substance thus obtained is intensely 

 alkaline. When purified by heat, which drives off the 

 sulphur and some other impurities, it becomes of a 

 white, bluish, or pearly cast, and is known as pearlash. 

 The lime used in its preparation acts to decompose the 

 sulphate of potash, which forms one of the salts of the 

 ashes, and frees the potash. 



The growing scarcity of wood has greatly decreased 

 the production of potash in this manner, as has also 

 the competition of foreign potish made from the beet- 

 root sugar waste and from the Stassfurt minerals. In 

 1880 the American product was 4,571.671 Ibs., valued 

 at $232,C43. Potash is a constituent of the abundant 

 mineral felspar, which, however, holds it with such 

 powerful affinity that it cannot be separated with suf- 

 ficient cheapness. It also exists to the amount of 10 

 or 12 per cent, in the mineral glauconitc of the cre- 

 taceous or greensand deposits of New Jersey. This is 

 more easily decomposed then felspar, and is capable of 



