18 PREPARATION AND MOUNTING 



Forceps are required in almost all microscopic manipulations, 

 and consequently are scarcely ever omitted from the microscopic 

 box, even the most meagrely furnished ; but of these there are 

 various modifications, which for certain purposes are more con- 

 venient than the usual form. The ordinary metal ones are em- 

 ployed for taking up small objects, thin glass, etc. ; but when 

 slides are to be held over a lamp, or in any position where the 

 fingers cannot conveniently be used, a different instrument must 

 be found. Of these there are many kinds; but Mr. Page's wooden 

 forceps serve the purpose very well. Two pieces of elastic wood 

 are strongly bound together at one end, so that they may be 

 easily opened at the othe'r, closing again by their own elasticity. 

 Through the first of these pieces is loosely passed a brass stud, 

 resembling a small screw, and fastened in the second, and through 

 the second a similar stud is taken and fixed in the first so that 

 on pressure of the studs the two strips of wood are opened to 

 admit a slide or other object required to be held in position. 

 The wood strips are generally used three or four inches long, one 

 inch wide, and about one-eighth inch thick. 



Again, some objects when placed upon the glass slide are of 

 such an elastic nature that no cement will secure the thin glass 

 covering until it becomes hard. This difficulty may be overcome 

 by various methods. The following are as good and simple as 

 any. Take two pieces of wood about two inches long, three- 

 quarters wide, and one-quarter thick ; and a small rounded piece 

 one inch long and one-quarter in diameter ; place this latter be- 

 twixt the two larger pieces. Over one end of the two combined 

 pass an india-rubber band. This will give a continual pressure, 

 and may be opened by bringing the two pieces together at 

 the other end; the pressure may be readily made uniform by 

 paring the points at the inner sides, and may be regulated by the 

 strength of the india-rubber band. These bands may be made 

 cheaply, and of any power, by procuring a piece of india-rubber 

 tubing of the width required, and cutting off certain breadths. 

 Another very simple method of getting this pressure is mentioned 

 in the " Micrographic Dictionary." Two pieces of whalebone of 

 the length required are tied together firmly at each end. It is 

 evident that any object placed betwixt them will be subject to 



