14 
METHODS IN PLANT HISTOLOGY 
of brass, 2 or 3 mm. in thickness, with three legs screwed into it. There 
should be long brass boxes to contain the paraffin. It is neither neces¬ 
sary nor desirable that the boxes have covers. Boxes are easily made 
from square brass tubing, 1 inch square. Cut the tube into pieces 
6 inches long, saw off one side, and solder pieces into the ends with 
hard solder. The brass plate can be heated with any kind of a flame 
at the pointed end. 
Since the Venetian turpentine method has almost entirely dis¬ 
placed the glycerin method, the turntable is becoming an unfamiliar 
object in the botanical laboratory; but some objects, like Nemalion 
and moss protonema, are still mounted in glycerin jelly, and so one 
still finds occasional use for this once necessary apparatus. A service¬ 
able form is shown in Figure 12. The more expensive turntables, 
Fig. 12.—Turntable 
with devices for automatic centering, present no practical advantages 
and the centering devices are often in the way. 
Scalpels made from thin razor blades have been mentioned 
already. For trimming paraffin blocks and handling paraffin ribbons 
a more rigid scalpel is necessary. A scalpel with a straight edge is 
preferable. 
Needles are used so constantly that it is well to have clamping 
holders. However, if it were not for the trouble of inserting and 
pulling out needles, nothing is quite equal to a rather large handle 
whittled out from a piece of light pine. 
Scissors are seldom used in the botanical laboratory except for 
cutting out labels. Rather stout scissors, with blades about 2| inches 
in length, are best for general purposes. 
It is convenient to have two pairs of forceps, a strong pair for 
handling slides and a delicate pair for handling covers. If there is 
