334 Miscellaneous. 



yards and at about 20 feet lower level, and also associated with 

 Glauber-salt, which, it is worthy of notice, is generally met with 

 here, according to the quarry men, in narrow seams at the line of 

 junction of the " hard plaster," (Anhydrite) with the soft " plas- 

 ter," (Gypsum). I detected it in the form of an opaque white 

 substance without lustre, and, to the naked eye, devoid of crys- 

 talline structure, in cakes and somewhat rounded masses varying 

 in size from that of a small pea to that of a bean ; these masses 

 lay between gypsum and crystals of Glauber-salt, taking shape 

 from the crystals of the latter on the side next to them, and when 

 detached from them leaving their faces, as it were, etched, and 

 sometimes the crystals were penetrated to a considerable depth 

 by the imbedded borate. The mineral is very soft, (H= 1) but 

 coherent, tasteless, slightly tough between the teeth, fuses readily 

 B.B. to a clear bead, insoluble in water, soluble in HCl. As 

 found, or very soon after being brought home, it lost by exposure 

 to air. Water = 1 8* 3 6 per cent, 



and the air dry substances gave the following results on analysis ; 

 the water was determined by ignition, the lime, magnesia and 

 sulphuric acid in one portion of the ignited residue, and the soda 

 in another, after its treatment with ftuor-spar and sulphuric acid 

 for separation of boracic acid, which was, of course, estimated 

 by deficiency : 



I. II. 



Lime, ^ 14-21 — — 



Soda, •7-25 



Sulphuric acid, 3-98 



Magnesia. 0-62 



Water, 19-96 20-78 



Boracic acid, 53-98 



100-00 

 The quantity of mineral obtained did not permit me to make 

 more than one analysis, and retain a little as a specimen for iden- 

 tification, but these results as well as the characters already men- 

 tioned, and the crystalline structure to which I shall presently 

 advert, are, I think, sufiicient to show that it is specifically 

 distinct from Natro boro-calcite (see analyses quoted.) On the 

 assumption that the magnesia and sulphuric acid are accidental, 

 and that the latter is combined with the former and with a quan- 

 tity of soda equivalent to that of the acid not required by the 

 magnesia, I have calculated the preceding results (i) after making 



