1899] MICROSCOPICAL JOURNAL. ITT 



well wetted with methylated spirit, and as the sections 

 are cut place them in a saucer of clean water. When 

 specimens are too small to be held by the hand, they may 

 be embedded in carrot. Take a piece of carrot, about an 

 inch long, cut it in half longitudinally, place the tissue 

 between the two halves, and tie together with some twine, 

 then proceed to cut the sections as before. Hand cutting 

 {» all very well for rough work, but it is very difficult to 

 get good even sections, and I would suggest that all stu- 

 dents should have a good microtome of some kind. 



Screw the microtome firmly to a table, and with a large 

 brass tube punch out a cylinder of carrot to fit into the 

 well of a microtome. Cut this in half longitudinally, and 

 with one of the smaller punches scoop out enough space 

 in one half of the carrot to take the specimen ; then place 

 the other half of a carrot in position, and make sure that 

 the specimen is held firmly between them, but of course, 

 it must not be crushed. Now put the cylinder of carrot 

 and specimen into the well of the microtome and cut the 

 sections. While cutting, keep the knife and the surface 

 of the microtome well wetted with methylated spirit,and 

 as the sections are cut place them in a saucer of water. 



In order to investigate the structure of a plant stem 

 correctly, it is necessary to have a longitudinal section as 

 well as a transverse. To obtain this, cut off about ^inch 

 of the stem transversely, and place it horizontally in the 

 groove of the carrot, with its flat ends against the walls 

 of the cavity, then place it in microtome and cut sections. 

 When the specimen has an irregular surface it must be 

 imbedded in paraffin. Take some paraffin wax and melt 

 over a water bath. Place the specimen in the well of the 

 microtome in the desired position, pour in enough paraffin 

 to cover it and allow it to cool, then cut sections as before. 



Bleaching. — Vegetable sections usually require bleach- 

 ing before they can be properly stained. Chlorinated 

 soda is used for this purpose. Take of dry chloride of 



