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 

 simultaneously. 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 

 0C., 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 



