ZINC SULPHIDE—Phosphorescent.
PITCHBLENDE—Specimens.
Write for particulars to
JOHN J. GRIFFIN & SONS, Ltd.,
20, 22, 24, 26, SARDINIA STREET, LONDON, W.C.
RADIUM APPLICATORS
Its employment in Therapeutics
and for scientific research.
(MacLeod) Surface, each 7s. 6d. Throat, £1 1s.