ZOOLOGY AND BOTANY, illCKOSCOPY, ETC. 



955 



handle 10 inches long, formed by a prolongation of the metal of the 



blade, firmly riveted between two pieces of wood. It resembles a T, 



the horizontal part being the wood, and the vertical one the handle. 



The blade is thick and chisel-edged, to prevent bending into the well 



when pressed firmly upon 



the cutting-plate. When Fig. 226. 



in use, the end of the 



handle is grasped by the 



right hand, while the little 



finger and adjacent palm 



of the open left hand are 



made to exercise steady 



pressure on the broad 



blade close to the handle. 



The breadth of the blade 



j)revents the hand from 



coming into contact with 



the section when cut. 



When a section is about 

 to be made, the blade is 

 placed in the ordinary 

 manner upon that part of 

 the cutting-plate nearest 

 to the operator. The edge 

 is then pressed firmly 

 against the plane of the 

 plate with the left hand, 

 at an angle of about 45°, 

 and the section shaved off 



by a rapid, steady, straightforward push of the edge through the tissue. 

 By observing these directions the largest sections can be made with 

 great rapidity, with perfect evenness, and with wonderful ease. In 

 the figure, A is a general view, and B is the section of the blade, C 

 being the edge which is held downwards in cutting. 



It may be asked, If the section is made by a simple push or 

 thrust, where is the necessity for a cutting edge 7^ inches long? 

 Why not use a broad knife at once? The reason for the extra 

 length of blade is twofold: firstly, because, to prevent bending of 

 the edge into the well, it is advisable to distribute the pressure 

 upon those parts of the cutting-plate which lie to each side of it ; 

 and secondly, because for certain tissues a drawing, or rather an 

 oblique pushing cut, is preferable to a straight thrust, and for such 

 a method of cutting a considerable length of edge is requisite. In 

 cutting nervous tissues, the knife should be slowly pushed through 

 with a steady equable pressure, when, if properly hardened, they will 

 curl themselves up on the back of the knife, and may then be trans- 

 ferred to a basin of water in the ordinary manner. 



The author claims that by this knife large and perfect sections 

 can be cut to almost any degree of thinness, with greater facility, 

 rapidity, and certainty than with the ordinary pattern. The difliculty 



