Contents, Vou. If. Parr II. 
Exrracts from Communications made to the Society : 
PAGE 
I. Onan Artificial Formation of Plumbago: by J. Auperson, Esq. with 
Remarks, by Professor CUMMING++ ee ese ees cee eeeeeereenees 44 
II. Experiments on Percussion: by B. BEVAN, Esq..seeseeeeessereeees 444 
III. Computed and Observed Variations of Magnetic Intensity: by R. W. Roru- 
MAN, Esqe. ssc cs cccerceccesescveneseceres cane ast. 00 td x44 
Donations to the Library.......+. SBRA GI ae Bist aie Geicieisae sa ieuine sik, a AAO 
Miatseiiine a iolaccetis braula nieieletatatele) gisielivlereivie # ereierstkie ) <400 
