CHAPTER X. 



SERIAL SECTION MOUNTING. 



185. Choice of a Method. I recommend the following : For 

 general work with paraffin sections, the combined water and albumen 

 method. 188. For very delicate work, the water method. For 

 collodion sections, the albumen method ; for large collodion sections, 

 GRAHAM KERR'S seems the most convenient. 



Methods for Paraffin Sections. 



186. The Water or Desiccation Method. GAULE (Arch. Anat. 

 Phys., Phys. Abth., 1881, p. 156) ; SUCHANNEK (Zeit. wiss. M.ik., 

 vii, 1891, p. 464) ; GULLAND (Journ. Anat. and Phys., xxvi, 1891, 

 p. 56) ; SCHIEFFERDECKER (Zeit. wiss. Mik., ix, 1892, p. 202) ; 

 HEIDENHAIN (Kern, und Protoplasma, p. 114) ; NUSBAUM (Anat. 

 Anz., xii, 2, 1896, p. 52) ; MAYER in the Grundzuge, LEE und MAYER, 

 1898, p. 113 ; DE GROOT (Zeit. wiss. Mik., xv, 1898, p. 62), and 

 others. The principle of this method is that the sections are made 

 to adhere to the slide without the intervention of any cementing 

 substance, being brought into intimate contact with the glass by 

 being slowly drawn down by the evaporation of a layer of water on 

 which they are floated. It is now practised, with unessential 

 variations, as follows : 



(a) For sections that are large and not numerous. The sections 

 are flattened out on water by one or other of the processes described 

 in 149. The slide is then drained and put away to dry until every 

 trace of water has completely evaporated away from under the 

 sections. This drying may be performed at the temperature of the 

 laboratory, in which case many hours will be necessary (to be safe 

 it will generally be necessary to leave the sections overnight). Or 

 it may be performed in a stove or on a water-bath at a temperature 

 a few degrees below the melting-point of the paraffin (best not above 

 40 C.), in which case fixation will be much more rapid, large thin 

 sections being often sufficiently fixed in an hour, though thick ones 

 will require half a dozen hours or more. The paraffin must not be 

 allowed to melt before the sections are perfectly dry ; the sections are 

 sure to become detached i'f it does. Perfectly dry sections have a 



