94 ESSAYS AND OBSERVATIONS 



' E X P E R. XVIII. 



The marie of Experiment^ 6. by burn* 

 ing loft near a third of its weight, and ac- 

 quired a very remarkable hardnefs. When 

 put into the water in this ftate, it did 

 r*ot relent in the fmalleft degree, though 

 naturally it diilolved readily in it. 

 The laminated marie of Experiment 7. 

 fuffered precifely the fame changes fron; 

 ]3urning. 



EX PER. XIX. 



The marie of Experiment 8. when 

 burnt and thrown into water, did not fall 

 freely into powder, but loofened into 

 pieces, which eafily yielded to the pref-^ 

 fure of the finger. This marie, before 

 burning, difTolved very flowly in water, 



EXPER, 



and fpungy texture, and acquiring little cohefion in the 

 fire, allows the water a» pafy acccfs to its calcarious 

 parth. 



