148 CHAPTER X. 



slide be one that lias been previously coated with a O5 per 

 cent, solution of white of egg and dried ; the collodion 

 adheres much more strongly to an albuminised surface. 



ATJBUETIN (Anat. Am., xiii, 1897, p. 90; Jo-urn. Roy. Mic. Soc., 1897, 

 p. 174) arranges on a clean slide, dehydrates the sections with blotting paper 

 and treatment with absolute alcohol, then drops on to them a mixture of 

 alcohol and ether which dissolves out the celloidin from the sections, then 

 allows the thin collodion thus formed to evaporate into a thin sheet on the 

 slide. Then 70 per cent, alcohol and other desired reagents. 



193. APATHY'S Oil of Bergamot Method (Mitt It. Zool. Stat. 

 Neapel, 1887, p. 742 ; Zeit. f. wi. Mil-., \, 1, 1888, p. 46, 

 and v, 3, 1888, p. 360; Jouni. Roy. Mic. ,SV., 1888, p. 670). 

 Cut with a knife smeared with yellow vaselin and wetted 

 with 95 per cent, alcohol. Float the sections, as cut, on. 

 bergamot oil (must be green, must mix perfectly with 90 per 

 cent, alcohol, and must not smell of turpentine), or on carbol- 

 xylol (Mikrotechnik, p. 176). The sections spread them- 

 selves out on the surface of the oil ; before they sink each 

 one is pushed by means of a needle into its place on a slip 

 of tracing-paper dipped into the oil. When the requisite 

 number of sections have been arranged on the paper, you 

 drain the paper, dry the under side of it with blotting-paper, 

 turn it over, and gently press it down with blotting-paper 

 on to a carefully dried slide. Remove the paper by rolling 

 it up from one end. The sections remain adhering to the 

 slide, and may have the remaining- bergamot oil removed 

 from them by means of a cigarette paper. If they are 

 already stained, nothing remains but to add balsam and a 

 cover. 



In the case of unstained or very small objects it is well to add a little 

 alcoholic solution of safranin to the bergamot oil. The celloidin of the sec- 

 tions becomes coloured in it in a few seconds, and malces them readily visible. 

 The colour disappears in a few days after mounting. 



The process may be much simplified (APATHY, Mikro- 

 teclni'ik, p. 127) by omitting the arrangement on the paper 

 and transferring the sections direct from the bergamot oil to 

 the slide, which (Hid., p. 176) may have been previously 

 collodionised and dried. The function of the bergamot oil 

 is to flatten out the sections. 



If the sections are to be stained, the slide after removal 



