118 SERIAL SECTION MOUNTING 



as cut, on bergamot oil (must be green, must mix perfectly with 

 90 per cent, alcohol, and must not smell of turpentine), or on 

 carbolxylol {Mikrotechnik, p. 176). The sections flatten themselves 

 out on the surface of the oil, and are then transferred to a slide 

 which (Apathy, Mikrotechnik, pp. 127 and 176) has been previously 

 collodionised and dried. 



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

 bergamot oil, by a cigarette paper, is exposed for a few minutes 

 to the vapour of a mixture of ether and alcohol, then brought 

 into 90 per cent, alcohol, and after a quarter of an hour therein 

 may be stained in any fluid that contains 70 per cent, alcohol 

 or more. 



If it be desired to stain in a watery fluid, care must have been 

 taken when arranging the sections to let the celloidin of each 

 section overlap that of its neighbours at the edges, so that the 

 ether vapour may fuse them all into one continuous plate. This 

 will become detached from the slide in watery fluids, and may 

 then be treated as a single section. Terpinol may be taken 

 instead of bergamot oil. 



219. Apathy's Series-on-the-Knife Method {Zeit. wiss. Mik., 

 vi, 1888, p. 168). The knife is well smeared with vaseline, rubbed 

 evenly on, and is wetted with alcohol of 70 to 90 per cent. As 

 fast as the sections are cut they are drawn with a needle or small 

 brush to a dry part of the blade, and there arranged in rows, 

 the celloidin of each section overlapping or at least touching that 

 of its neighbours. When a series (or several series, if you like) 

 has been thus completed, the sections are dried by laying blotting- 

 paper on them, and the series is painted over with some of the 

 thinnest celloidin solution used for imbedding, is allowed to 

 evaporate for five minutes in the air, and the knife is then removed 

 and brought for half an hour into 70 per cent, alcohol. This 

 hardens the celloidin around the sections into a continuous 

 lamella, which can be easily detached by means of a scalpel, and 

 stained, or further treated as desired. 



220. Weigert's Collodion Method {Zeit. wiss. Mikr., 1885, 

 p. 490). Slides, or larger plates of glass, are prepared by coating 

 them with collodion in a thin layer, as photographers do, and 

 allowing them to dry (they may be kept thus in stock). Sections 

 (cut wet with alcohol) are got on to one of these (by a round- 

 about process, not essential) and arranged in order, and gently 

 pressed down with paper. 



Now remove with blotting-paper any excess of alcohol that 

 may remain on or around the sections, pour collodion over them, 

 and get it to spread in an even layer. As soon as this layer is 

 dry at the surface you may write any necessary indications on it 

 with a small brush charged with methylen blue (the colour will 

 remain fast throughout all subsequent manipulations). 



