416 Scientific Intelligence. 
ile 
rapidly and gives decided indications. 
mospheric electricity. : 
He has verified on some serene days a diurnal periodicity in the 
electricity, as remarked by Schubler and others. . a 
e finds that the interior even of storm clouds is always positive, 
except during the shock of lightning, or in the case of rain, hail or 
a rain storm commencing a long distance from t 
place of observation, and carried over this place by the wind, 
observes that when the storm is far off the electricity is positive, grad- 
ually increasing with the progress of the storm; when the storm 
comes near, the electricity is strongly negative, often producing sparks. 
d i J 
usual condition. Between each period there is a momentary neull 
point. The distance at which the rain begins to induce negative elec 
tricity is very variable, sometimes at 30 miles, and other times when 
the first drops begin ‘The rain hence occupies a r ener 
with positive electricity surrounded by a zone of negative plecinen 
When there ar uccessive showers of rain, these Its “im 
. t ra 
lime ; the bell glass is then filled through the tubulure with carbonic 
acid, the tube supplying this gas reaching to the bottom of the bell 
glass; after the atmospheric air is thus excluded, the tubulu 
metically closed by a stopper through which passes @ tube 
bulb containing water at the exterior end, while the interior 
is near the lime. There is no action of the lime while it is dry, 94” 
warming the bulb, water falls on the lime, and soon after, the cat bs 
cid is absorbed, while at the same time the moisture is taken up PY 
the sulphuric acid. : : he 
Ammonia may also be employed, with some modifications of 
, 164. 
re is her- 
ha 
