RUDGE. 



Phil. Mag. Ser. 6, Vol. 25, PL TIL 



Fig. 5. — Starch. 



Fig. 6. — Sulphur 



Fig. 7. — Boracic Acid. 



Fig. 8. — Aluminium. 



:g. 9, — Sifted Sulphur upon a charged surface. Fig. 10. — Sulphur on a positively charged surface. 



