72 On Enhydros found at Beechworth. 



sions ; one of wliicli appears to be quite filled up with 

 quartz crystals, the other containing, besides an inner lining 

 of quartz crystals, also a mobile fluid, and a bubble of air. 

 The air bubble was transferable from place to place within 

 the cavit}^, as the position of the specimen was altered. 

 The remains of the specimen, which I submit for your 

 inspection, are still in such a state as to convey a fair idea 

 of its original form and character. 



To extract the fluid, a fragment was first broken from 

 one of the corners of the stone. This disclosed a fine open- 

 ing or pore in the quartz lining, connected with the inner 

 cavity. The specimen was now placed under the receiver of 

 an air-pump, and as the exhaustion proceeded the air bubble 

 in the water stone expanding extruded the fluid, drop by 

 drop, through the pore. In all fully eighteen drops of 

 fluid were thus collected in a carefully-cleaned test-glass. 

 The fluid, thus extracted, was perfectly pellucid, but 

 contained a few minute angular transparent fragments, 

 apparently splinters of quartz. 



The fluid is water, but slightly mineralized. A single 

 drop evaporated on glass leaves a slight residue, forming a 

 gummy annular outline, but affording distinct evidence of 

 crystallization when examined under the microscope. 

 When 15 drops of the fluid were evaporated in a watch- 

 glass over oil of vitrei in vacuo, the fluid froze, giving out 

 air-bubbles, which vesiculated the icy crust; the ice gradually 

 disappearing left a small residue, nearly white in colour, 

 non-crystalline, and wrinkled on the surface. A few small 

 crystals and some larger (possibly hexagonal plates) were 

 observed in the mass when examined microscopically. 



A small crop of beautiful microscopical crystals was 

 obtained on re-solution and spontaneous evaporation. 

 Among these, cubic crystals and crystals pertaining to 

 the cubic system were recognized. On dissolving up 

 the crystals a delicate impress of their form was left 

 — white on a delicately pale yellow ground, as though 

 a deposit of colloidal ferruginous silica remained, with 

 colourless cavities where the crystals had occupied position. 



On testing the redissolved saline matter it gave a distinct 

 white flocculent precipitate with nitrate of silver, imme- 

 diately soluble in ammonia. It also gave a granular pre- 

 cipitate with chloride of barium. With ammonia and 

 oxalate of a.mmonia a very slight granular precipitate was 

 obtained after some time ; and with ammonia, chloride of 



