118 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(&) the microscopic portion of the same enlarged, and (c) in the matter 

 of chemistry and physics, the experiment in actual operation." 



The mahogany body is hexagonal, and each of the three front sides 

 is provided with condensers and projecting arrangements. The back 

 opens to give access to the radiant, which in this case is a Brockie-Pell 

 arc-lamp ; but, if necessary, a lime-light can be readily substituted. The 

 lamp is fixed to the base-board, 3 ft. square, and the body can be rotated 

 through 60° on either side of the central position, thus allowing any of 

 the three nozzles to be directed towards the screen. The three sets of 

 condensers are placed so that their axes intersect at a point about which 

 the radiant is placed. The centre nozzle is fitted as a lantern Micro- 

 scope, with the Microscope-attachment described in the preceding note, 

 with alum cell and various sets of condensing lenses and objectives, and a 

 space in front of the main condensers is provided for polarizing ap- 

 paratus. The focusing arrangement consists of a skew rack and pinion 

 and a fine screw adjustment ; and the whole Microscope can be easily 

 removed and a table-polari scope substituted. The right-hand nozzle is 

 arranged for the projection of ordinary lantern-slides, and the left-hand 

 one is provided with an adjustable slit for spectrum work. A small 

 table sliding on rails serves to carry the prisms, and the same rails 

 support projecting lenses. 



Due de Chaulnes' Microscope. — In the Museo di Fisica, Florence, 

 we recently saw the Microscope shown in fig. 9, and by the courtesy 



