rOL. I.] J'HILOSOPHICAL TRANSACTIONS. 123 



in the trunk of the tree, has contracted a petrified crust about the thickness of a 

 shilling, all over the woody part within the bark; the marks of the axe also re- 

 maining very conspicuous with this petrified crust upon it. By what means it 

 should thus happen cannot well be conceived, as there is no water near it, and as 

 the part is above the ground, and the tree still growing: unless, being perhaps 

 cut at a season when the sap was flowing, the oozing of the sap might become 

 petrified by the air, and the tree grow rotten and hollow inward since that time. 



Inquiries concerning Mines. By Mr. Boyle, N" 19, p- 330. 



These queries are reduced by the author to six heads : 



I. The neighbouring country about the mines. II. The soil where the mines 

 are. III. The signs of mines. IV. The structure and other particulars belong- 

 ing to the mines themselves. V. The nature and circumstances of the ore. 

 VI. The reduction of the ore into metal. 



/. Queries on the neighbouring Country. 



Whether the country be mountainous, plain, or distinguished with vales? 

 Whether high or low, &c. fruitful or barren, cold or temperate, rocky or not, 

 hollow or solid ? Whether they run in ridges or seem confusedly placed ; and, 

 if the former, what way the ridges run north and south, &c. &c. 



Whether the country be barren or fruitful ? What it produces, and what it 

 most abounds in ? 



What cattle it nourishes, and what their nature and peculiarities ? 



The diseases and lives of the inhabitants longer or shorter than ordinary ? 



The rivers, brooks, springs, and other waters ; and the nature of them ? 



Whether the air be dry or moist, hot or cold, clear or foggy, thick or 

 thin, heavy or light ; any subterraneous streams, and what they are ? 



//. The Soil. 



Whether the soil be stony ; and, if it be, what kind of stones it abounds with ? 

 Whether it be clayey, marly, chalky, &c. ? 



///. The Signs or Indications of Mines. 



By what signs they know or guess that there is a mine in such a place? 



Whether it be observed that trees and other greater plants seem to have their 

 tops burned, or other leaves or outsides discoloured ? Or whether there be any 

 plants that affect to grow over such mines, or the contrary ? 



What colour the stones and pebbles take in the brooks, springs, or other 



a 2 



