488 SUMMARY OF CURRENT RESEARCHES RELATING TO 
difficult to batlie the knife with sufficient spirit to prevent them from 
tearing. (2) The vibration in the unsupported end of the blade. 
(3) The fact that, in most cases, a change in the obliquity of the edge 
of the blade, which may become necessary during cutting, is always 
accompanied by a change in its plane, and therefore by the loss of 
several sections. (4) The difficulty of adjusting the tissue to be cut to 
any desired plane. 
I have devised an instrument to meet these difficulties so that it is 
possible — (1) to cut sections with a knife completely under spirit ; 
(2) to support the knife by both ends ; (3) to change the cutting edge 
of the knife to any obliquity desired without altering its plane ; (4) to 
allow of ready adjustment of the tissue by means of a simple mechanism 
Fig. 77. 
w.s. 
I ! 
Microtome seen from the side. 
for holding the block of wood on which the tissue is mounted, and of its 
easy orientation by means of a ball-and-socket joint. 
The instrument consists (figs. 77 and 78) essentially of the follow- 
ing parts: — (1) A long shallow trough (DD, fig. 78) for holding spirit. 
(2) A wedge slide W S, which moves along a groove (B, fig. 78) on one 
side of the trough, and supports the knife K by two horizontal arms 
H H. (3) A screw mechanism G- passing through the centre of the 
trough for carrying and raising the tissue that is to be cut. (4) A 
treadle-arrangement (fig. 77) automatically raising the section. 
The trough D is 36 in. long, 8 in. broad, and 1 in. deep. In the 
centre is a well C, 7 in. square and 2^ in. deep. To the middle of 
the floor of this well is attached the apparatus G for raising the tissue 
