30 DR BREWSTER on the Existence of Two New Fluids 



which had a sort of triangular form, one of the sides of the tri- 

 angle being about one-tenth of an inch long. The fluid was 

 quite transparent ; and, as the air-bubble was not perceptibly di- 

 minished by heat, there is every reason to think that the fluid is 

 water. The crystals were transparent to a considerable degree, 

 and had a white milky tint, when seen by reflected light. 



In considering the. circumstan es of this singular phenome- 

 non, we are led to suppose, that the included crystals had been 

 dissolved in the fluid at the time of its being shut up in 

 the quartz, and had afterwards been deposited from the solution. 

 The ingenious supposition of Sir HUMPHRY DAVY, that a liquid 

 hydrate of silica may exist at high temperatures, and may con- 

 tain small quantities of atmospheric air, will no doubt explain 

 the phenomena of water in rock-crystals ; but it is not easy to 

 comprehend how the formation of a group of crystals could ei- 

 ther have accompanied or followed the separation of the water 

 and the silex. 



As the specimen now alluded to is too valuable to be destroy- 

 ed, for the purpose of analysing the minute crystals, it is pro- 

 bable, that our information respecting them would have been 

 very limited, had not a circumstance of an accidental nature en- 

 abled me to throw some farther light on the subject. Several 

 years ago, when I was examining, along with Earl COMPTON, a 

 large collection of quartz crystals from Quebec, for the purpose 

 of obtaining remarkable crystallizations, I was much struck with 

 the appearance of several spherical groups of whitish crystals, 

 within some of the specimens. Upon pointing out to Lord 

 COMPTON this peculiarity, his Lordship agreed with me in think- 

 ing that they belonged to the Zeolite Family. Having pur- 

 chased all the specimens that could be found, I have since re- 

 peatedly examined the included crystals, with the view of deter- 

 mining their nature. I found that they did not belong to the 

 zeolites, but consisted principally of carbonate of lime ; and, as 



