APPENDIX. 497 



the requirements of this volume are concerned. The 

 edge should be kept permanently sharp. 



Before cutting, pare away the imbedding material, so 

 as to reduce that which surrounds the preparation to the 

 minimum. 



Mounting. 



Transfer the sections as cut, paraffin and all, to micro- 

 scopic slides previously prepared by one of the two 

 undermentioned methods, and proceed as directed in 

 either case. 



a. White of egg method. 



Smear the surface of the slide with a thin but uniform 

 film of freshly drawn white of egg and deposit the 

 sections in order of cutting. Gently heat the slide 

 until the paraffin begins to melt and then put it aside. 

 When set, put the whole bodily into turpentine and 

 leave it until all the paraffin is dissolved out ; upon ex- 

 amination the sections will be found to be firmly at- 

 tached to the glass slide by means of the coagulated 

 albumen. 



Immersion in turpentine for an indefinite period 

 will do no harm. 



b. Kreasote and shellac method. 



Smear the surface of the slide with a heated solution 

 of white shellac in Kreasote. Submit the whole to the 

 temperature of the melting point of the paraffin until 

 the kreasote is evaporated, whereupon the sections will 

 become firmly adherent to the glass by means of the 

 shellac. Next immerse the whole in turpentine, and 

 leave it at rest until the excess of imbedding material 

 is dissolved out. 



This method is best applicable to preparations which 

 have been previously stained and clarified. The white 

 of egg process is not only the simpler of the two, but 

 the more advantageous, as the sections may be cut and 



M. 3 2 



