16 



as great a variety of structure and origin as possible, were examined 

 In some cases the sum of the water and carbonic acid was determined 

 by ascertaining the loss by ignition ; but in several cases every consti- 

 tuent was separately determined, and great care was especially taken in 

 estimating the amount of carbonic acid. The following contains the 

 description of the specimens, and the results of the analyses : — 



I. — Compact indistinctly laminated mass, with its upper surface co- 

 vered with ripple marks ; colour, pure white, opaque ; dull, earthy, but 

 with a slightly conchoidal fracture, and fissile along the planes of deposi- 

 tion ; somewhat brittle, streak shining. Hardness = 2. Specific gravity, 

 2*232, or 3'758 after it has become fully saturated with moisture. The 

 piece examined was taken from the centre of the mass, which was twelve 

 centimetres long, ten wide, and eight thick. 



II. — Fragment taken from the exterior of the last-mentioned mass, 

 which had been many months exposed to the air. 



III. — Light, porous, friable mass, of a perfectly white colour, and 

 not unlike some kinds of meerschaum, but much more friable, being easily 

 reduced to powder between the fingers. 



lY., Y., VI. — Specimens of compact white hydrocarbonate, similar 

 to I. and II. 



YII. — Compact white hydrocarbonate, very distinctly laminated, and 

 slightly discoloured from clay, &c., on the surfaces of the laminae; formed 

 part of the floor in which the bones were buried. 



YIII.— Another specimen of light, friable sinter, similar to III., 

 but having a faint rose-red tint. 



IX. — Fragment of the hydrocarbonate encasing a piece of bone. 

 Some of the layers, though perfectly opaque, had a fibrous structure, like 

 silicate of zinc. 



X. — Part of a lump of pure white compact hydrocarbonate, enclosed 

 in translucent crystalline Smithsonite. 



XI Part of a lump of pure white compact hydrocarbonate, inter- 

 mixed with white transparent fibrous silicate of zinc. 



XII.— External layer of a stalactite, having a distinctly fibrous 

 structure, analogous to that of the silicate. 



XIII. — Ball of white hydrocarbonate of zinc, one centimetre in dia- 

 meter. 



I. II. III. 



Oxide of Zinc, . 74-059 . . . 74-244 . . . 73-581 

 Lime, .... 0-011 . . . O'OIS . . . 0-010 

 Phosphate of iron, 0-008 . . . 0-005 . . . 0-003 



Alkalies in combi- )q.qq3 



nation with silica, ) 

 Carbonic acid, 14-934) 14-893) 14-980) 



Hydrated water, 10-070 25-968 10-027 25-656 10-421/ 26-429 

 Hygroscopic water, 0-964) 0-736) 1-028) 



Organic matter, . traces . . . traces . . . traces. 



100-049 



99-918 100-023 



