172 



IMBEDDING METHODS. 



paper several times round it so as to make a projecting collar, 

 and stick a pin through the bottom of the paper into the 

 cork. For work with fluid masses, such as celloidin, the 

 cork may be leaded at the bottom to prevent it from floating 

 when the whole is thrown into spirit or other liquid for hard- 

 ening (Fig. 2). 



LEUCKHAKT'S Imbedding Boxes are made of two pieces of 

 type-metal (Fig. 3). Each of these 

 pieces has the form of a carpenter's 

 " square " with the end of the shorter 

 arm triangularly enlarged outwards. 

 The box is constructed by placing the 

 two pieces together on a plate of glass 

 which has been wetted with glycerin 

 and gently warmed. The area of the 

 box will evidently vary according to 

 the position given to the pieces, but 

 the height can be varied only by using 

 different sets of pieces. In such a box 

 the paraffin may be kept in a liquid 

 state by warming now and then over a 

 spirit lamp, and small objects be placed 

 in any desired position under the microscope (Journ. Roy. 

 NIC. Soc. [N.S.], ii, p. 880). 



SELENKA has described and figured a simple but perhaps 

 more efficacious apparatus having the same object. It con- 

 sists of a glass tube, through which a stream of warm water 

 may be passed and changed for cold as desired, the object 

 being placed in a depression in the middle of the tube (see 

 Zool. Anz. t 1885, p. 419). A modification of this method is 

 described by ANDEEWS in Amer. Natural., 1887, p. 101 ; cf. 

 Zeit.f. wiss. Mik., iv, 3, 1887, p. 375. 



For small paraffin objects the following procedure is very 

 useful. The object is removed from the paraffin solution, the 

 superfluous fluid is removed by means of blotting-paper, and 

 the object placed on a cylinder of paraffin. A piece of stout 

 iron wire is now heated in the flame of a spirit lamp, aud with 

 it a hole is melted in the end of the cylinder; the specimen is 

 pushed into the melted paraffin, and placed in any desired 

 position. The advantages of the method lie in the quickness 

 and certainty with which it can be performed. 



FIG. 3. 



