332 LETERS ON NATURAL MAGIC. 



Several such strata were often found in the same 

 specimen, sometimes parallel to each other, at 

 other times inclined, and forming all varieties of 

 angles with the faces of the original crystal. 



These cavities, which occurred in sapphire, 

 chrysoberyl, topaz, beryl, quartz, amethyst, peridot, 

 and other substances, were sometimes sufficiently 

 large to be distinctly seen by the naked eye, but 

 most frequently they were so small as to require 

 a high magnifying power to be well seen, and 

 often they were so exceedingly minute, that the 

 highest magnifying powers were unable to exhibit 

 their outline. 



The greater number of these cavities, whether 

 large or small, contained two new fluids different 

 from any hitherto known, and possessing remark- 

 able physical properties. These two fluids are in 

 general perfectly transparent and colourless, and 

 they exist in the same cavity in actual contact, 

 without mixing together in the slightest degree. 

 One of them expands thirty times more than 

 water, and at a temperature of about 80 of 

 Fahrenheit it expands so as to fill up the vacuity 

 Fig. 80. 



in the cavity. This will be understood from the 

 annexed figure, where A B C D is the cavity, m n 

 p o the highly expansible fluid in which at low 



