SOURNAL 
ASIATJIC SOCIETY OF BENGAL. 
New Series. 
Vol. XVI.—1920. 
en a 
1. The Utility of Desiccants in Electrostatic 
easurements. 
By V. H. Jackson, M.A., and A. T. Muxersen, M.A. 
Preliminary tests on the relative efficiency of Calcium 
chloride and strong Sulphuric acid in protecting from the 
) 
used in physical apparatus for accurate. Electrostatic measure- 
ments were described in a paper published by us in 1914.! 
These tests were however open to the objection that the 
sealing of the case within which the insulators of the electro- 
meter and other apparatus used for the measurements were 
enclosed was not hermetical. In the following series the mea - 
surements have been made with an improved form of appar 
tus,” in which the Dolezalek electrometer and the fhanlators 
were enclosed in a case from which the moist external air is 
absolutely excluded, so that the comparisons between the 
various desiccants used were carried out under strictly uni- 
form conditions. As before, we consider that the maximum 
rate of leak which is permissible with a satisfactory degree 
of insulation of the quadrants is 0-01 volt per minute, when 
the quadrants are initially charged to about one volt. 
I. Catctum CHLORIDE. 
solid and easily procurable desiccant being desirable, 
Calcions chloride was again the first substance examined but, 
in confirmation of the earlier results, proved quite unsatisfac- 
! Journal and Proceedings A.S. S. , Vol. X, 1914, pages 227-240. 
2 This Journal Vol. XVI, page 1 
