32-i Scientific Intelligence. 



derived from the dolomite of the quarries in the Binnenthal, 

 Switzerland. Hutchinsonite, named after Dr. Arthur Hutchin- 

 son, of the University of Cambridge, is a species occurring in 

 prismatic orthorhombic crystals, with numerous terminal faces. 

 The color is gray to grayish black, and the streak vermilion. 

 The crystals are transparent to nearly opaque. Hardness, 1*5-2 ; 

 cleavage, good, parallel to the macropinacoid. In composition it 

 is found by G. T. Prior to be a sulpharsenite of thallium, lead, 

 silver and copper ; it contains nearly 20 per cent of the rare 

 element thallium. 



Smithite, named after Mr. G. F. Herbert Smith of the British 

 Museum, occurs in monoclinic crystals, resembling flattened hexag- 

 onal prisms, with prominent bas alplane. The lustre is adamantine, 

 the color light red, and the streak vermilion. The crystals are 

 transparent to translucent. Hardness, 1*5-2; cleavage, parallel to 

 the orthopinacoid, perfect. The surface of the crystals changes on 

 exposure to light from pure red to orange red. According to G. 

 T. Prior, the composition is expressed by the formula AgAsS a . 



Trechmannite, after Dr. C. O. Trechmann, occurs very spar- 

 ingly in minute rhombohedral crystals resembling the two species 

 hutchinsonite and smithite in color, streak and hardness. The 

 crystals showed portions of hexagonal prisms, with small pyra- 

 midal and rhombohedral faces. Cleavage was observed perpen- 

 dicular to the prism. The composition is as yet undetermined. 



Maiuute, named after Dr. John Edward Marr of Cambridge, 

 occurs in highly modified monoclinic crystals, usually doubly 

 terminated. The color is lead- to steel-gray, the surface showing 

 iridescent tarnish ; the luster is metallic, brilliant. The hardness 

 is 3 and the fracture conchoidal; no cleavage was observed. 

 Only a single specimen had been found at the time the descrip- 

 tion was published ; this showed some fifteen small crystals im- 

 planted upon the dolomite, hence though the crystallographic 

 data are complete the composition is yet to be determined. 



Lengenbachite, named after the Lengenbach, a tributary 

 stream in the Binnenthal, occurs in bladed crystals often very 

 thin and sometimes curled up like paper. They show a highly 

 perfect cleavage and splendent luster ; the crystals are appar- 

 ently twinned and are inferred to belong to the triclinic system. 

 The plates are flexible and somewhat malleable but not elastic. 

 The color is steel-gray, often with iridescent tarnish, the luster 

 metallic ; the specific gravity is 5'80. In composition it is essen- 

 tially a sulpharsenite of lead with small amounts of antimony, 

 silver and copper, as determined by A. Hutchinson. 



Bowmanite, named after H. L. Bowman of the University of 

 Oxford, occurs in rhombohedral crystals with basic cleavage and 

 having the form of six-sided plates, often grouped in rosettes ; 

 the crystals show a pseudo-symmetry in the basal sections. The 

 color is honey-yellow, the luster brilliant vitreous to resinous. 

 The hardness is 4*5, the specific gravity 3*2. According to Bow- 

 man it is essentially a phosphate of lime and alumina with small 

 amounts of iron, water and possibly magnesia. 



