778 HAEMATITE 



undertaken by the Sub-Wealden Exploration Committee. The gypseous deposits are 

 upwards of fifty feet in thickness, and occur in beds, which are probably of Purbeck 

 age. No gypseous deposits of equal extent, on this geological horizon, had been previously 

 known in this country. The great deposits of gypsum worked at Montmartre and 

 elsewhere in the neighbourhood of Paris from which ' Plaster-of-Paris ' borrows its 

 name occur in the Eocene beds of the Paris basin, equivalent to certain strata re- 

 presented in this country in the Isle of Wight. See ALABASTKB ; PLASTEB-OF-PAUIS. 



H 



HABANA BROWN. This name has been given to aniline-brown. See 

 AXILINE-BROWN. 



HACKLE. A flax comb. See FLAX. 



HADDOCK. The Morrhua ceglefinus, one of the Gadida, or cod tribe. 



HADE. A miner's term, used in Derbyshire and some of the northern counties, 

 signifying the inclination or deviation from the vertical of any mineral vein or lode. 

 Hadings signify that some parts of the veins incline, while others are vertical. 



HJEIVX ATZXT. A product of the decomposition of hcemoglobin, or the red- colouring 

 matter of the blood. The name h(ematin was also given by Chevroul to a crystalline 

 substance, of a pale pink colour, and brilliant lustre when viewed in a lens, which he 

 extracted from logwood. See HJEMATOXYLIN. 



Scientific terms with prefixes similar to that of hcematin are derived from the Greek 

 a!/ji.a, blood. 



HJEIVTATINTONE. A kind of glass used by the ancients for making ornamental 

 vessels, mosaics, &c. It is described by Pliny, and has been found pretty abundantly 

 in the excavations of Pompeii. This glass is of a beautiful red colour, but the colour 

 disappears on melting. Von Pettenkofer obtained a similar glass, which he has called 

 astralite, by melting a mixture of silica, lime, calcined magnesia, litharge, soda, copper- 

 hammerings, and smithy-scales. See ASTRALITE. 



HJE1V1 ATITE. Native peroxide of iron. In true haematite, sometimes called for 

 distinction's sake red h<smatite, the oxide is anhydrous, whilst in the so-called brown 

 fusmatite it is hydrated. 



The haematite proper occurs in a remarkable manner in irregular deposits in carboni- 

 ferous limestone, at Whitehaven in Cumberland, and at Ulverstone in Lancashire. 

 The following analysis of the Whitehaven ore of Cleator Moor by Mr. A. Dick, shows 

 its peculiar character : 



Peroxide of iron .95*16 



Protoxide of manganese 0'24 



Lime 0'07 



Phosphoric acid traco 



Sulphuric acid traco 



Bisulphide of iron traco 



Insoluble residue . 5*68 



101-15 

 Iron, total amount 66'60 



The following analysis of the Ulverstone ore is by the same chemist : 



Gillbrow Ore. 



Peroxide of iron 86'50 



Protoxide of manganese 0-21 



Lime 277 



Magnesia T46 



Carbonic acid ........ 2*96 



Phosphoric acid trace 



Sulphuric acid 0-11 



Insoluble residue ....... 6*55 



100-50 

 Iron, total amount .**. 60'55 



