104 



necessary well-infiltrated tissue and a hard, firm collodion mass. 



58. Transferring the sections. If the sections are quite 

 thick they may be transferred from the knife to a slide or a dish by 

 means of forceps or a brush ; if they are thin, however, it is better 

 to handle them by means of an absorbent tissue paper, as follows : 

 Flood the sections well with clarifier and then by means of a pipette 

 remove the clarifier from the knife and place over the sections the 

 end of a piece of the tissue paper, pressing it clown upon the sec- 

 tions if necessary. Carefully pull the paper off the edge of the 

 knife ; the sections will adhere to the paper. .Place the paper, sec- 

 tions down, on a slide, taking care that the sections are in the de- 

 sired position. With the finger carefully press the sections (through 

 the transfer paper) to the slide, and then lift the paper, with a roll- 

 ing motion, from the slide ; the sections will adhere to the slide. 

 Should they stick to the paper instead, lower the paper again and 

 again firmly press the section to the slide. For further proceedure 

 see 66, 68. If it is not desired to mount the sections upon a 

 slide immediately, or if they are to be kept in bulk, as for class 

 work, the transfer paper may be shaken gently in a dish of clarifier 

 or 95% alcohol and the section (or sections) will float free and sink 

 to the bottom. 



59. If it is desired to mount the sections in a series, proceed 

 as follows : With an artist's brush draw the first section, when cut, 

 up toward the back of the knife and make the next section. Place 

 this section to the right of the first, and so on, arranging them in 

 serial order, section after section, and line below line, until enough 

 are cut to fill the area that the cover-glass will cover. Flood the 

 sections as before by letting the clarifier flow over them, being care- 

 ful, however, not to float them from their places. Absorb the clari- 

 fier from the knife with a pipette, and place over the sections a 

 piece of the transfer paper twice the width of a slide ; press it down 

 if necessary, and slowly draw it off the edge of the knife. Should 

 some of the sections adhere to the knife instead of the paper, it 

 means that the clarifier had been allowed to thicken* on them, 



* If one is a long time cutting a series of sections, it sometimes occurs that 

 the xylene evaporates leaving the castor oil that is thick and viscid and also a 

 solvent of the collodion, so that the sections are not easily transferable but 

 stick rather firmly to the knife. In such a case, fresh clarifier or even a little 

 xylene to dissolve the castor oil must be used. 



