150 CHAPTER X. 



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 the next section is being 

 cut, with the sections upwards on a moist surface prepared 

 by arranging several layers of blotting-paper, covered with 

 one layer of closet paper, in a plate, and saturating the 

 whole with alcohol. When all the sections have been 

 arranged on the slip, you pass to the next stage of the pro- 

 cess, the collodionisation of the series. 



This is done in two steps. The first of these consists in 

 transporting the series on to a plate of glass prepared with 

 collodion. The plate is prepared beforehand by pouring 011 

 to it collodion and causing it to spread out into a thin layer, 

 as photographers do, and allowing it to dry. (A number of 

 the plates may be prepared and kept indefinitely in stock ; 

 microscope slides will do for series of small sections.) Take 

 one of these plates ; lay the slip of paper with the sections 

 on the plate, the sections downwards ; press it down gently 

 and evenly, and the sections will adhere to the collodion ; 

 then carefully remove the paper. (Do not place more than 

 one or at most two lines of sections on the same plate, for 

 those first placed run the risk of becoming dry whilst you 

 are placing the others.) This finishes the first stage of the 

 collodionising process. 



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 indi- 

 cations on it with a small brush charged with methylen blue 

 (the colour will remain fast throughout all subsequent 

 manipulations) . 



The plate may now either be put away till wanted in 80 



