222 
rOPULAR SCIENCE EEYIEVr. 
tlie society upon its improved position, and severally reviewed tlie various- 
matters whicli have been brought under the notice of the Fellows during 
the year. 
A Gas Slide for Microscopical W ork. — In the supplement to Schultzes 
Arcliiv (Bd. 3, Ht. 3), Herr Strieker describes a slide so constructed that 
currents of any gas may be introduced and allowed to operate on an object 
whilst under examination in the field of the microscope, and which may 
also be employed for the transmission of electric currents to the object. The 
following is an account of its construction, which the reader will better 
comprehend by referring to the Microscopical Journal for January. In the 
middle of a piece of thickish glass a circular groove is cut, and from this is 
channelled a straight furrow of the same depth to each end. In each of 
these furrows is placed a slender metallic tube, preferably of platinum, and 
each having at its extremity a small bulbous enlargement, for the purpose,, 
when needed, of affixing caoutchouc tubes. These metallic tubes are 
cemented into the furrows by means of shellac or other suitable cement, 
and thus serve as the sole means of communication with the circular furrow. 
The whole surface of the glass is now covered either with a layer of paper 
or of some varnish, but in either case has a circular space left open in the- 
centre. The object of the paper or other covering is to keep the covering 
glass at a suitable distance from the central circular portion of glass upon 
which the object to be examined is placed. 
A Novel Microscope Lamp . — Mr. Charles Collins has shown us a contrivance, 
devised by Mr. Fiddian of Birmingham, and manufactured by him, which 
LAMP WITH CHIMNEY ATTACHED. CHIMNEY OF LAMP. 
so entirely surpasses in efficiency everything we have before seen, that we must 
give a short account of it. It is a modification of the parabolic reflecting 
chimney recently constructed by Mr. Collins for the Bucket-lamp. It i» 
simply a copper chimney expanding into a sphere below, as shown in the 
