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On a form of Leaf-holder for the Microscope^ and a 
Revolving Slide-holder with Selenite Stage. By 
James Smith^ F.L.S. 
(Eead May 9th, 1866.) 
On a Leaf-holder for the Microscope. 
The instrument to wMcli I would this evening venture to 
draw the attention of the Society, and which 1 have called 
a leaf-holder, as indicating the class of objects for which it 
was designed and is best adapted, is intended to supply a 
want I have often felt in the examination of leaves, feathers, 
wings of moths, and other similar large flat objects which 
frequently require to be placed in a particular position, both 
as regards the microscope and the source of illumination. I 
have also found, in observing aphides or minute fungi upon 
the surfaces of leaves, very great difficulty in getting the 
object into a good position for examination, the ordinary 
stage forceps being in some cases almost useless for the pur- 
pose. 
In the above set of drawings, a, shows the double ring form- 
ing the clip, made of a thin elastic yellow metal ; b, the foun- 
dation ring, upon which the others work ; c, the complete 
instrument with leaf inserted ; and d, the small holder for 
such minute objects as could not be well held by the rings 
alone. 
The ring b, which forms the foundation upon which the 
others rotate, may be made of somewhat stouter metal, the 
piece projecting at the side forming the socket to attach it to 
the stem, as shown in c. In the double ring forming the 
