202 AQUA REGIA. 



crclioiwry hard phosphate of lime, known as phosphorite. These deposits -were de- 

 scribed in 1844 by the late Dr. Daubeny, and have boon worked for many years on a 

 very extensive scale. In the neighbourhood of Staffel, near Liraburg, on the Lahn, 

 and elsewhere in Nassau, valuable deposits of phosphorite have been actively worked. 

 At Staffel the phosphorite is sometimes incrusted with a peculiar mineral, generally 

 in botryoidal or reniform masses, termed Staffdite. This may have been derived 

 from the alteration of the phosphorite, and is said to contain, in addition to phosphate 

 of lime, upwards of 9 per cent, of carbonate of lime, and is further peculiar in con- 

 taining traces of iodine. Phosphorite is also worked at Amborg, Diez, and other 

 localities in Bavaria. The mineral called Osteolite is said by Professor Church to bo 

 an altered impure form of apatite. In the United States there are a largo number of 

 localities yielding apatite. Crystals of considerable size have been found in St. 

 Lawrence co., in Orange co., in Rossie, and elsewhere in the State of New York. At 

 Hurdstone, in Sussex co., New Jersey, ' a shaft has been sunk, and the apatite mined ; 

 masses brought out weigh occasionally 200 Ibs., and some cleavage prisms have the 

 planes 3 in. wide ' (Dana). Apatite is widely disseminated through many of the 

 crystalline limestones of the Laurentian series in Canada ; indeed, in some parts of 

 the limestone it is so abundant as to form a large proportion of the rock. The most 

 remarkable deposits of Laurentian apatite are in the townships of Burgess and 

 Elmsley. ' In North Elmsley it forms an irregular bed parallel to the stratification of 

 the limestone ; the breadth of the bed seems to be about 10 feet, of which 3 feet are 

 nearly pure crystalline apatite, sea-green in colour, and with a small admixture of 

 black mica. Masses of this gave an average of 88 per cent, of phosphate of lime ' 

 (T. Sterry Hunt). 



When apatite or phosphorite occurs in sufficient quantity to be systematically worked, 

 it becomes a mineral of great commercial value. Treated with oil of vitriol, it is 

 converted into superphosphate of lime, and in this soluble form is highly valued by 

 the agriculturist as a fertilising agent for the soil. Apatite has also been used, in 

 the place of bone-ash, as a constituent of certain kinds of soft porcelain. For other 

 mineral substances containing phosphate of lime, see SOMBBERITE, COPROLITES, and 

 Gt-ANo. F.W.R. 



APPIiES. The fruit of the Pyrus malm (apple-tree). Employed in the manu- 

 facture of cider. See CIDER. 



APPXiE-TREE. (Pyrus mains.) The wood of the apple-tree is much used in 

 the Tunbridge turnery manufacture, and the millwright employs the wood of the 

 crab-tree for the teeth of mortice wheels. 



APPLE-WINE. Cider. Winckler finds that the wine from apples is dis- 

 tinguished from the wine from grapes by the absence of bitartrate of potash and of 

 oenanthic acid, by its containing a smaller amount of alcohol and more tannin, but 

 especially by the presence of a characteristic acid, which he regards as lactic acid, 

 notwithstanding that this opinion is not confirmed by the degree of solubility of its 

 salts with oxide of zinc, lime, and magnesia. See CIDER. 



AQUAFORTIS. Nitric acid, somewhat dilute, was so named by the alchemists 

 on account of its strong solvent and corrosive action upon many mineral, vege- 

 table, and animal substances. It is still employed as the commercial name of nitric 

 acid. See NITRIC ACID. 



This acid is usually obtained by distilling either common nitre or cubic nitre with 

 sulphuric acid. 



It may, however, be usefully borne in mind, that this term of aquafortis, or strong 

 water of the old chemist, was also applied to solutions which answered their special 

 purposes. Thus Salmon, in 1685, gives the composition of aquafortis from certain 

 mixtures of acids, not nitric, and salts, and distinctly refers to the Pharmacopoeia for 

 the other kind. This may be of service when applying old recipes for processes in 

 the arts. Aquafortis did not always mean nitric acid. 



AQUAMARINE is the name given to those varieties of beryl which are of clear 

 shades of sky-blue, or greenish-blue. It occurs in longitudinally-striated hexagonal 

 crystals, sometimes a foot long, and is found in the Brazils, Hindostan, and Siberia. 

 See BERYI,. 



AQUA REGIA. Royal water. The name given by the alchemists to that mix- 

 ture of nitric and muriatic acids which was best fitted to dissolve gold ; it is now 

 called nitro-muriatic acid, or nitro-chlorohydric acid, or hypochloro-nitric acid. 



Aqua regia, prepared under different conditions, appears to give different results. 

 Gay-LuBsac observed that aqua regia, when heated in a water-bath, evolves a gaseous 

 body which, dried and exposed to a frigorific mixture, separates into chlorine and a 

 dark lemon-yellow liquid, boiling at 70 F. This yellow liquid was found to contain 

 69'4 per cent, of chlorine, the calculated quantity for the formula, N0 2 CP, being 70'2. 

 Cray-Lussac refutes the assertion of E. Davy and Baudrimont, that the properties of 



