JOURNAL 



OF 



NATURAL PHILOSOPHY, CHEMISTRY, 



AND THE ARTS : 



ILLUSTRATED WITH ENGRAVIitGS. 



BY WILLIAM NICHOLSON. 



VOL. IV. 



LONDON: 



PRINTED rOR THE AUTHOR, BY W. STRATFORD, CROWM-COURT, TEMPLE-BARJ 



AND SOLD By G. G. AND J. ROBINSON, PATBRNOSTER-ROW. 



M,DCCCL 



