242 Specific Examples of Slide Making 



sharp scalpel which is moved with a rocking motion, picked up on a 

 camel's-hair brush, and transferred to another sheet of black paper. The 

 remains of the ribbon may be thrown away. 



The sections in each of the selected strips of ribbon are counted to 

 determine the maximum number of slides that may be made— the ear 

 sections are usually the limiting factor— and the pieces of ribbon trimmed, 

 each to contain approximately the same number of sections. Then the re- 

 quired number of slides are cleaned and a few drops of the usual adhesive 

 added to 25 ml of filtered distilled water in a small flask. 



The only difficulty of the procedure consists in persuading each section 

 to occupy its correct place on the slide. This is carried out most easily 

 by the following technique. A single slide is taken, placed in front of 

 the operator, and covered lightly with the diluted adhesive. The fluid 

 should extend to the edge of the slide but should not be raised in a 

 meniscus sufficiently high to cause any appreciable slope of the fluid 

 from the center of the slide toward the edges. Using a sharp scalpel, the 

 end section is cut, with a rocking motion, from each of the ribbons. These 

 sections are placed in the correct order but without any regard to sym- 

 metry on the surface of the fluid on the slide. To secure these sections 

 in the required position, it is necessary to have two fine brushes, a 

 mounted needle, and a bunsen burner or spirit lamp. 



The last section (that is, the section which is to lie farthest from the 

 label on the slide) is now secured in position with a brush held in the 

 left hand, while the second section is maneuvered with a brush held in 

 the right hand until its edges touch those of the first section. Both sections 

 will be held together by capillary attraction when the brush is removed. 

 The needle is warmed in the flame and used to fuse the edges of the 

 sections together in two spots. If the entire edge is melted, it will cause 

 a ridge which will prevent the compound ribbon from lying flat against 

 the slide; two minute spots fused together with the point of the needle 

 are sufficient to hold the section in place. The needle is laid down, and 

 the brush again picked up with the right hand and used to guide the 

 next section into its appropriate place. This section is spotted into position 

 with the tip of the warm needle, and so on, until all the sections have 

 been fused into a continuous ribbon. Then the slide is placed in the 

 usual way upon the warm table until such time as the ribbons have flat- 

 tened; they are drained in the manner described under the section on 

 section-cutting technique and then pressed to the slide with a wet filter 

 paper and rubber roller, if this is the method of operation preferred by the 

 technician. The compound ribbon, of course, may be guided into the 

 center of the slide, while the latter is still wet, before it is pressed or dried. 

 The sections are left, in the ordinary course of events, on the warm table 

 until they are entirely dry before being dewaxed in xylene and brought 



