ON STAINING FLUIDS, AND STAINING. 127 



Dr. Fearnley's ether freezing microtome. This is 

 simply the top of the Grove- Williams' microtome, 

 fitted with a clamp and screw arrangement for 

 attaching it to the work-bench. The ether nozzle is 

 immediately under the frame of the glass plate, and 

 the bottle of ether stands under the machine on the 

 table as shown in wood-cut. Fearnley's microtome 

 is also made by Messrs. Swift & Son. 



Cathcart's Microtome. 



This is an ether freezing microtome for use either 

 with a stout razor, or with a plane iron. Cathcart's 

 invention, used with a plane iron, for cheapness, sim- 

 plicity, and efficacy cannot be surpassed, if equalled, 

 by any ether or ice microtome we know of. With 

 the expenditure of two drachms of ether, the operator 

 can cut sixty or seventy sections in almost as many 

 seconds, every section being of exquisite thinoess. 

 The ether used is methylated ether of 720 s.g. 



The freezing process has already been described. 

 This being accomplished, the tissue is elevated to the 

 knife by a very small fraction of a revolution of 

 the screw with the left hand, whilst the right drives 

 the plane iron. The iron must be held with the 

 edge far below the level of the rest of the iron, and 

 the screw movement and the push of the iron move- 

 ment must take place alternately. When a mass 

 of sections has accumulated on the iron, it must be 

 floated off into a saucer of water. (See illustration 

 on page 128.) 



An admirable and most useful microtome is made 

 by Zeiss. It can be seen at the depot of, and 

 purchased from, his London agent, Mr. C. Baker. 



