IN TROD UC TION. 1 1 



quently freshened by a few light passes along a 

 leathern strop. 



Section-Cutting with the Microtome. Although it is 

 very important for every worker in Normal Histology to 

 be able to cut thin sections with the free hand, it is de- 

 sirable in many cases to make use of an instrument called 

 the Microtome for this purpose ; since, when many sec- 

 tions are to be cut, much time is thereby saved, and 

 sections can be made much thinner and smoother. One 

 of the best instruments is that devised by Prof. R. 

 Thoma, of Heidelberg, and known as Thomas Micro- 

 tome. This instrument is made of three sizes, and the 

 intermediate or largest size is most useful. This can be 

 imported from the maker, Rudolph Jung, of Heidelberg, 

 Germany. The method of using the instrument need 

 not be described here, since with the instrument at hand 

 any worker will readily make out for himself the necessary 

 procedure. 



The instrument and mode of using are described in 

 Jour. Royal Microscopical Soc., vol. iii., p. 298, 1883. 



The Freezing Microtome. For many purposes it is de- 

 sirable to study thin sections of fresh tissues which have 

 not been subjected to the action of hardening agents. 

 Such sections are best prepared with a so-called freezing 

 microtome, by means of which, by the action usually of a 

 spray of ether or rhigolene, small pieces of tissue may in a 

 few seconds be made hard and easily cut off in thin slices. 

 The freezing microtome of Thoma is one of the simplest 

 and cheapest, and can be obtained as above. A thin bit of 

 the fresh tissue, not more than 2-3 mm, thick, is placed 



