356 Minerals. 



been for the time in which they were collected, were later 

 replaced by others which better illustrated the characters of 

 minerals. Neither Mr. Courten nor Sir Hans Sloane had made 

 a special study of minerals ; in their time the interest of a 

 mineral specimen was generally limited to the yield of valuable 

 metal or to the utility as an ornamental stone. For it was not 

 till twenty years after the death of Sir Hans Sloane that crystal- 

 line form was discovered to be a specific character of unorganised 

 matter ; till then, attention had rarely been paid, in the collecting 

 of mineral specimens, either to excellence of crystalline develop- 

 ment or to variety of crystalline form. Further, oxygen being 

 still undiscovered, chemistry had not yet entered upon its 

 modern phase. The sharp definition of mineral species and their 

 scientific arrangement were alike impossible. 



The point to which mineralogy had attained during the life- 

 time of Sir Hans Sloane himself is well illustrated by the scheme 

 of classification adopted for the mineral section of his manuscript 

 catalogue, the making of which was begun in the early years of 

 the eighteenth century, and was continued till his death. The 

 minerals were distributed into the following classes : (1) Precious 

 Stones ; (2) Metals ; (3) Ambers, Bitumens, Ambergris, &c. 

 (including Sulphur) ; (4) Salts, Earths, Clays ; (5) Talcs, Micas ; 

 (6) Crystals; (7) Flints, Fossils, &c. The assignation of the 

 specimens to these classes was very imperfect, and there was 

 much overlapping; that of Precious Stones, for example, 

 included Bristol Stones, Agates, Touchstone, Loadstone, many 

 Flints, and also Stones of Curious Shapes. In the will of Sir 

 Hans Sloane it was expressly stated that the catalogue had 

 been prepared in great haste. The total number of entries in 

 the mineral section, which occupies three volumes, is 8649. 

 Other volumes contain an elaborate set of indexes. 



Most of the Sloane specimens now preserved in the Collection 

 are worked articles (cups, bowls, boxes, knife-handles, &c.) of 

 agate, jasper, rock-crystal, and other varieties of quartz. Mention 

 may also be made of faceted pebbles of amethyst and aquamarine 

 from India, a cut turquoise, two specimens of amber, and the first 

 described specimen of columbite. 



1758. 



A mocha-stone, set in an enamelled ring : presented by the 

 Duke of Noja. 



