CHAPTER XI 

 SERIAL SECTION MOUNTING 



207. Choice of a Method. We recommend the following : — 

 For general work with paraffin sections, the combined xvater and 

 albumen method, § 210. For very delicate work, the ivater method. 

 For collodion sections, the albumen method ; for large collodion 

 sections, Graham Kerr's seems the most convenient. 



METHODS FOR PARAFFIN SECTIONS 



208. The Water or Desiccation Method. Gaule {Arch. Anat. 

 Phys., Phys. Abth., 1881, p. 156) ; Suchannek {Zeit. iviss. Mik., 

 vii, 1891, p. 464) ; Gulland {Journ. Anat. and Phys., xxvi, 

 1891, p. 56) ; ScHiEFFERDECKER {Zeit. ti'iss. Mik., ix, 1892, 

 p. 202) ; Heidenhain {Kern, und Protojjlasma, 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 § 169. 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 beloiv 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 allorved to melt before the sections 

 are perfectly dry ; the sections are sure to become detached if it 

 does. Perfectly dry sections have a certain brilliant transparent 

 look that is easily recognisable. As soon as dry the paraffin may 

 be removed, and they may be further treated as desired. To 

 remove the paraffin all that is requisite is to put the slide in a 



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