300 



[ CH. X 



FIG. 236 A B. A paraffin holder clamp and a razor support for the 

 Jllinot Microtome for utilizing most of the cutting edge. ( Trans. Amer. 

 Micr. Soc., 1901.) 



Clamp for the paraffin block holder. In A it is shoivn in section, in a 

 side view. With this clamp one can use stove bolts as well as the expensive 

 paraffin holders furnished with the instrument. A laboratory can have as 

 many paraffin block holders as necessary without undue expense. 



FIG. 237 A B. Razor Support and Razor. 



(A) Support with heavy base and vertical piece. The base should be 

 capable of moving endwise one or two centimeters to bring the opening in the 

 vertical part opposite the paraffin block. (B) Front piece to the razor. 



FIG. 238. Razor with straight back and edge. By moving this back and 

 forth on the support nearly the entire cutting edge can be utilized. 



FIG. 239 A B. The knife support of the microtome with the razor support 

 and razor in position. 



(A) Front view ; (B} Back view, in which the inclination of the knife 

 tozvard the paraffin block is shown. 



With a pipette (Fig. 240) put several drops ot water on the 

 slide and then place a piece of a ribbon on the water; or put the sec- 

 tions on the albumenized slide and add the water afterward. Heat 



FIG. 240. Reagent bottle with combined cork and pipette 

 ( This is made by taking a cork of the proper size and making 

 in it a hole with a cork borer for the glass tube. It is advan- 

 tageous to have a string tied tightly around the rubber bulb as 

 shown) . 



the slide carefully over a spirit lamp or gas flame, being sure not 

 to melt the paraffin. As the water warms the paraffin expands and 

 stretches the sections out smooth. A copper heating plate also, 

 Fig. 241, is excellent for spreading sections. 



