WEIGERT'S COLLODION METHOD. 181 



326 a. Apathy's Series-on-the-Knife Method (Zeit. f. wiss. 

 Mik., vi, 2, 1888, p. 168). The following is in some respects- 

 more convenient than the oil of bergamot method. The knife 

 is well smeared with yellow vaselin rubbed evenly on with the 

 finger, 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 touch- 

 ing that of its neighbours. The rows are of the length of the 

 cover-glass, and are arranged one under the other so as to form 

 a square of the size of the cover-glass. When a series (or 

 several series, if you like) has been thus completed, the sections 

 are dried by laying blotting-paper on them (there is no risk 

 of their becoming attached to it, as they are held down by the 

 vaselin) . The series is then painted over with some of the 

 thickest celloidin solution used for imbedding, is allowed to 

 evaporate for five minutes in the air, and is then either wetted 

 with 70 per cent, alcohol, and allowed to remain whilst cutting 

 is proceeded with, or (if no more sections are to be cut, or if 

 the knife is now full) the knife is 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. It is well to bring it at once on to a slide, 

 moisten the edges of the celloidin plate with ether and alcohol 

 mixture, so that it may not become detached, and bring the 

 whole into the staining solution. 



327. Weigert's Collodion Method (Zeit. f. wiss. Mik., 1885, 

 p. 490). Sections are cut wet, with alcohol. Care should be 

 taken not to have so much alcohol on the knife as to cause 

 the sections to float. Prepare a slip of porous but tough paper 

 (Weigert recommends "closet paper"), of about twice the width 

 of the sections. Soak it in alcohol, take it by both ends, 

 stretch it slightly, and lower it on to the section that is on the 

 knife. The section will adhere to the paper, and is taken up 

 by moving the slip horizontally or slightly upwards, away from 

 the edge of the knife. Take up the first section towards the 

 end of the paper that you hold in your left hand, and let the 

 remaining sections follow in order from left to right. After 

 each section has been taken up, the slip is placed, whilst 



