[ 177 1 



APPENDIX. 



No. I. 



SPECIFIC GRAVITY OF SOME OF THE FOREGOING RESULTS. 



AS many of the artificial Iimeftones and marbles produced in 

 thefe experiments, were poffefTed of great hardnefs and com- 

 paclnefs, and as they had vifibly undergone a great diminution 

 of bulk, and felt heavy in the hand, it feemed to me an object of 

 fome confequence to afcertain their fpecific gravity, compared 

 with each other, and with the original fubftances from which 

 they were formed. As the original was commonly a mafs of 

 chalk in the lump, which, on being plunged into water, begins 

 to abforb it rapidly, and continues to do fo during a long time, 

 fo as to vary the weight at every inftant, it was impoflible, till 

 the abforption was complete, to obtain any certain refult ; and 

 to allow for the weight thus gained, required the application of 

 Vox, VI.— P.I. Z a 



