216 Scientifie Intelligence. 
by adding to the beaker a sufficient quantity of water. No 
further attention is required till the operation is completed by 
removing the upper funnel and washing its inner surface, 
together with the outer surface of the short arm of the syphon; 
on which some drops of liquid are often thrown by the bursting 
of air bubbles, when the level of the liquid in the beaker sinks 
below the end of the syphon. 
The advantages of this method of filtration are—that any 
amount of liquid can be passed through a small filter without 
attention ; that liquid and precipitate can be transferred with 
less liability to loss than by the usual methods; that the appara- 
tus can be adjusted for use in less than a minute; and that it is 
composed of parts which may be said to involve no additional 
expense ; also, that if the precipitate is not too bulky, its whole 
washing may be effected without attention during the passage 
_ of the wash-water. 
70 c.c. water, 83 minutes; the passage of 85 c.c. wash-water, 
10¢ minutes. Attention was given during 104 minutes, while 
Western Reserve College, Hudson, Ohio, May, 1873. 
SCIENTIFIC INTELLIGENCE. 
IL Puysics AND CHEMISTRY. 
1. On the reflection of Solar heat from the sg “4108 of Lake 
Geneva.—L, DuFovur, in a communication to the French Acad- 
emy of Sciences (June 30, 1873), states that he has used the 
central thermometer. Three such bulbs were used; the first pro- 
tected by suitable screens gave the atmospheric temperature ; 
i hs sun received the heat 
fix the ratio between the heat reflected from the lake and the 
direct solar radiation, The calculation requisite to determine 
