5$ .TRAVELS THROUGH 



fire, fmce I have a great many evidences of the 

 contrary, and of their aqueous origin by indura- 

 tion, 



pofc, (hat jn -fome harder pieces of white Icbes, kept in Mr. 

 anh'j Iceland collection, there appears a Gratified white chal- 

 cedony, which cannot be considered as adventitious, and un- 

 doubtedly is produced either by a finer fediment, or by ita 

 greater faturation; proving, that the fubilantial earth of chal- 

 cedony and lebes are the fame, and that both are nearly related 

 to the lapis nephriticus, the ferpentinc, the bacon-flone, the 

 amianth, and the talc, which are found in many volcanic 

 places; and according to Mr. Marggrafs experiments, have 

 been by ,many Minerr-logiUs wrongly placed among the argil- 

 laceous itones. 



Similar operations of properly qualified hot wells, fo com- 

 mon and various in volcanic countries, might very well, anfwer 

 for the jafpers, agates, and other flints, in the china clays 

 and boles. But whether they have, in fact,, produced them, 

 muft be left to future proper enquiries in the volcanic coun- 

 tries, where they are fo very common. 



jafper is found in large beds and rocks in Sicily, near .Rrrgw, 

 ,in the Apennines ; ?,t Mfmtieri in the Saneje (LETTER vii.) ; 

 near Frandenlerg and Ca/ett in Hefien (ilid.)\ in Iceland 

 (Mr. Banks'* cabinet) j and x perhaps, in many other countries 

 .equally famous for their being volcanic. Marine bodies un- 

 certain whether ever inclofed in them* 



The agates, equally deftitute of marine bodies, are very 

 plenty in Sicily : and. to the Tranflator's knowlege> in great 

 varieties of colours, found in fome veins or their nodules. 



The Common Jlints feem, to the Tranflator, to be rather fatu- 



rated and glued parts of old marine fediment-beds. He found 



them either flecking ia, the calcareous ilrata of fine grained 



iinieflone as produced in them, or in dragged and waihed de 



6 cays 



