177 



On a New Method of Mounting Microscopical Objects. 



By Professor H. L. Smith, Hobart College, Geneva, N.Y. 



Communicated by Mr. T. Curties. 



{Read May 26, 1876.) 



I have noticed so many enquiries lately as to the best mode of 

 mounting objects requiring a cell of moderate depth, and often the 

 use of a fluid, that I am induced to give a short description of my 

 own method, both for Diatomaceae and for Foraminifera. For the 

 latter I punch, out of a sheet of wax (dark-green or black), a disk 

 a trifle larger than the brass curtain-ring which is to constitute the 

 wall of the cell. This disk is pressed by one edge to the centre of 

 a glass slide, and slowly warmed till it melts — if well done no 

 bubble of air is enclosed under it, and the whole cools with a 

 smooth, somewhat dead surface. The ring is then pressed into this, 

 and centred by the turn-table, and then again pressed fully home, 

 showing the brass, when looked at from the under side ; and the 

 whole finished with the usual " Brunswick black " outside, and also 

 the ring inside. To attach the Foraminifera, or other objects, a 

 minute drop of turpentine is applied to the wax, and in a minute 

 or so, before it is quite dry (and we may proceed leisurely), the 

 object is placed on the softened wax ; when thoroughly dry, it will 

 be found so strongly attached that a violent blow or a fall will not 

 dislodge it. Of course, if the object is very large the turpentine 

 may have a little of the Brunswick black, or some size dissolved in 

 it. The improvement over the glistening gum attachment for 

 minute objects is very manifest — indeed no signs of the cementing 

 material show if the turpentine is judiciously used. While all this 

 is being done, the Brunswick black on the brass ring will have set 

 sufficiently to fasten the cover, which should be of such a size as to 

 rest, not on the top of the ring, but to slip just within, so that its 

 surface will be flush with the top of the ring. Wlfen the cover is 



