216 Scientific Intelligence. 
SCIENTIFIC INTELLIGENCE. 
JI. CHEMISTRY AND PHYSICS. 
1. Improved Filter-pump.—Prof. T. E. Toorre has devised an 
improved form of Jogno’s modification of the filter-pump, which 
possesses some advantages over the ordinary form. It consists of 
a vertical tube A about one meter in length and from 8 to 10 milli- 
meters in diameter, having inserted perpendicularly into it, a short 
distance below the upper end, a side tube B, about 5 centimeters 
ong. The upper end of A, which is cut off obliquely, is connected 
by means of a strong but sufficiently elastic rubber tube with the 
stopcock regulating the water-supply. In the original form of the 
apparatus the end of the side-tube was narrowed somewhat, so 
that when the end of the rubber tube from the flask to be evacu- 
The end 
1, 
The action is similar to that of the hydraulic ram, and the appar 
atus, unlike the earlier form, requires only a sufficient head of 
Experi 
. some months since, with a view 
to the production of photographic copies of diffraction-gratings 
