M. Siramler on the Liquids contained in certain Minerals. 279 



cavities, the liquid exhibited various comportments : sometimes 

 they vanished instantaneously, and without leaving a trace ; at 

 others they disappeared more slowly, leaving a fixed residue. 

 Hitherto no satisfactory explanation has been aflforded of these 

 phsenomeua. 



Simmler,in a paper in Poggendorflf's Annalen"^, has put forth 

 the view that the expansible liquid may in many of the cases have 

 been liquid carbonic acid. 



Brewster first determined the coefficient of expansion of the 

 more expansible liquid, and found that between 10° and 26° it 

 expanded from 1-000 to 1-250, or a quarter of its bulk ; between 

 the same limits water would only expand from 1-000 to 1-003; 

 hence the liquid expands eighty-three times as much as water. 

 According to Thilorier's experiments, the expansion of liquid 

 carbonic acid between 0° and 30° C. is from 100 to 145, which 

 gives 0-015 as the coefficient of expansion for 1° C. Now this 

 agrees almost exactly with the coefficient of expansion of Brew- 

 ster's expansible liquid, which is, between the observed limits, 

 1-01497 for 1 degree Centigrade. 



With reference to the refrangibility of the liquid, Brewster 

 found it to be less than that of water, which is 1-3358, though 

 not alike in all cases. In a Siberian amethyst he found it to be 

 = 1-1106, and in a Brazilian topaz =1-1311. The refrangibility 

 of liquid carbonic acid does not appear to have been numerically 

 determined. Davy and Faraday say that it refracts light more 

 feebly than water, while Niemann states that its refrangibility 

 is almost equal to that of water. 



Thilorier and i\Iitchell state that liquid carbonic acid is not 

 miscible with water, and floats on it like ether. Brewster ob- 

 served the same of the expansible liquid. 



The expansible liquid was in many cases under great pressure, 

 producing in some cases an explosion when the mineral was 

 broken. Some of the liquids, when the cavities had been bored 

 into, rose slowly to the surface, spread out, and assumed a rota- 

 tory motion. Simmler suggests that this phrenomenon is expli- 

 cable on the assumption of a spheroidal condition. Natterer 

 observed that liquid protoxide of nitrogen might be preserved 

 for some time in an open glass. Of compressible gases which 

 might possibly exist in nature, there are, besides carbonic acid, 

 sulphuretted hydrogen, phosphurctted hydrogen, hydrochloric 

 acid, ammonia, and sulphurous acid; and each of these would 

 have been detected by the smell. 



In another paper f Simmler suggests that diamond might 

 possibly be also a product of crystallization from liquid carbonic 



• December 1858. t Ibid. 



