20 Cutting the Sections. 



It will be found a great saving of time, when a num- 

 ber of specimens are to be cut at one freezing, not to 

 have the material too thick, as a piece a quarter of an 

 inch thick will give an enormous number of thin sec- 

 tions, and take only a short time to freeze. 



To MAKE MUCILAGE. 



Pour warm water on picked gum Acacia and make a 

 solution rather thicker than the mucilages sold in the 

 shops. 



CUTTING THE SECTIONS. 



Eemove all the specimens to be cut, from the gum, 

 and place them in a small saucer ready at hand. Take 

 up one with a pair of forceps and lay it on the circular 

 plate of the microtome, drop some gum solution on it 

 with a small brush, and see that it runs down on to the 

 plate all round the specimen so as to fix ib firmly. 

 When it is thoroughly frozen adjust the razor so that 

 ib will just pass over without touching, and then lower 

 the screw at the apex of the triangle by giving it a 

 slight turn to the left and push the knife across the 

 material in a diagonal direction. Have a small vessel 

 ready containing warm distilled water. It is necessary 

 to use disbilled water, as in ordinary water the lime in 

 solution is precipitated by boiling and the specimen will 

 be covered by fine particles of carbonate of lime and 

 utterly ruined. Moisten the upper surface of the razor 

 with gum solution, and the sections as they are cut will 

 slip up on it without curling, carefully remove them 

 with a camel-hair brush and place them in the warm 



