370 APPENDIX. 



In cutting not very large sections, a dozen or more 

 sections may be cut in rapid succession; the sec- 

 tions heap up on the razor, and may be removed 

 to water with a camel-hair brush; three or more 

 pieces of a well hardened tissue may thus be cut 

 simultaifeously. In cutting large sections, it is best 

 to place on the razor a number of small drops 

 of water and to cut slowly; the section folds up on 

 the razor. The razor (with the frame) should then be 

 dipped under water and the section floated off; it 

 should be taken out on a glass slide and treated 

 on the slide with 30, 50, 75 p.c. alcohol, etc. ; care 

 should be taken to remove as much as possible of 

 the clearing agent, otherwise the Canada balsam in 

 which the section is mounted may remain a long 

 time fluid. Smaller sections should be treated in 

 the glass dish or watch glass-with the various 

 reagents. 



Sections of imbedded tissues may also be cut with the 

 microtome, but as a rule this is more trouble than, 

 and has no advantage over, the freezing method. 



Fresh tissues should be frozen as little as possible below 

 0°C., they are apt to shew crossing bands brought 

 about by the crystallization of the water in them ; they 

 should be transferred with a brush to salt solution. 

 If it is required to stain them they should be 

 transferred to 30 p.c. alcohol and treated with 

 Spiller's purple, methylene blue or methyl-violet or 

 removed from 30 p.c. to stronger alcohol and stained 

 with carmine, hsematoxylin, etc. 



When one or two tissues only are to be cut, it is 

 simpler to use a microtome with ether spray as the 



