554 



PHOSPHOR-BRONZE 



is converted into the acid phosphate of lime. The usual practice is to mix Lone-dust 

 with one-fourth of its weight of oil of vitriol, adding an equal quantity of water after 

 each portion of acid ; the mass is allowed to remain in a heap until quite dry. It is 

 then sold as superphosphate, which is a mixture of the gelatinous portion of the bone 

 with the acid phosphate and sulphate of lime. See APATITE ; BONES ; COPROLITE. 



Phosphate of Magnesia enters into the composition of the bones of animals. 



Amongst the native phosphates may be enumerated : 



Apatite. Phosphate of lime, the composition of which mineral is generally, phos- 

 phoric acid, 42'26 ; lime, SO'OO ; fluorine, 3'77. See APATITE. 



Wagncrite. Phosphate of magnesia, with fluoride of magnesium. 



Zwicselite. Phosphate of iron and manganese. See IRON. 



Pyromorphitc. Phosphate of lead. See LEAD. 



Lazulite. Blue spar. See LAZULITE. 



Turquoise. See TURQUOISE. 



Vivianite. Blue iron earth or phosphate of iron. Sec IUON. 



Libethenite. Phosphate of copper. See COPPEK. 



Ehlite. A hydrous phosphate of copper. 



Wavellitc. Sub-phosphate of alumina. 



Childrcnite, consists of phosphoric acid, 27'8 ; alumina, 14'1; protoxide of iron, 

 31'3 ; protoxite of manganese, 8'9 ; water, 17'6. 



Phosphochaldte. Hydrous phosphate of copper. 



Dufrenitc. Green iron ore. Phosphoric acid, 28'0 ; peroxide of iron, 63' 1 ; water, 8'9. 



Uranite. Two varieties of this mineral are recognised : the one is a copper-uranite, 

 known as Torbnerite, and consisting of a phosphate of uranium and copper ; the other 

 is a lime-uranite, known as Autunite, and composed of phosphate of uranium and lime. 



Cryptolite. Phosphate of cerium. 



Xcnotime. Phosphate of yttria. 



There are some other combinations which it is unnecessary to describe. 



PHOSPHATXC NODULES. Concretions and nodules of phosphate of lime, 

 which occur in layers chiefly in the Gault and Upper Greenland, and also in the 

 Crag. They are now much used lor artificial manure. See COPROLITES. 



PHOSPHOR-BRONZE. Although the combination of phosphorus with copper, 

 tin, zinc, and other alloys, dates a good way back, it is but yesterday since anything 

 like a careful and skilful investigation of the physical properties of these combinations 

 was undertaken. 



The latest and most important of the experimental data as to the physical constants 

 of phosphor-bronze which have been obtained are the following: 



Prussian Experiments. By order of the Royal Prussian Ministry of Commerce ex- 

 periments have been made with various sorts of phosphor-bronze. These experiments 

 are carried on at the Royal Academy of Industry at Berlin. The object of these 

 experiments is to ascertain the qualities and capacities of the metal whilst under 

 heavy strain, and especially the comparative resistance to often-repeated strains, 

 whether tensile or inflecting. The first bar of phosphor-bronze fixed on the stretching 

 machine was tried under a constant strain of 10 tons per square inch, and resisted 

 408,230 pulls of this amount. A bar of ordinary bronze broke even before the strain 

 of 10 tons per square inch had been attained. A second bar of phosphor-bronze was 

 tried under a strain of 12.J tons per square inch; and under this high strain withstood 

 1 47,850 pulls. Yet more favourable results have been obtained on a machine by which 

 the test-bar is repeatedly bent up to 40,000 times per day. A bar of phosphor-bronze 

 whilst under 10 tons of strain per square inch resisted 862,980 bends, while best gun- 

 metal broke after 102,650 bends. Another bar of phosphor-bronze under 9 tons strain 

 per square inch is being tested, and has at present resisted 1,260,000 bends. 



Austrian Experiments. At the Imperial Austrian Polytechnic Institution in Vienna, 

 experiments were executed by Professor R. Jeuney with phosphor-bronze bars, showing 

 the following results : 



In the Imperial Arsenal at Vienna, experiments were made by Colonel Uchatitii", 

 giving the following results : 



