KULTSCHIZKY'S CELLOIDIN-PARAFFJN METHOD. 165 



298. Clearing and Mounting. You may mount in glycerin 

 without removing the mass, which remains as clear as glass 

 in that medium. 



You may mount in balsam, also without removing the mass, 

 which does no harm, and serves the useful purpose of holding 

 the parts of the sections together during the manipulations. 

 Dehydrate in alcohol of 95 or 96 per cent, (not absolute, as 

 this attacks the collodion). Clear with a substance that does 

 not dissolve collodion. The clearing agents most recommended 

 are origanum oil (01. Origan, cretici should be taken, not 01. 

 Orig. gallici), bergamot oil (said to make sections shrink 

 somewhat) ; oil of sandal wood ; lavender oil ; oil of cedar 

 wood (safe and gives excellent results, but acts rather slowly) ; 

 chloroform; xylol, or benzin (may make sections shrink if 

 not well dehydrated) ; or Dunham's mixture of three or four 

 parts of white oil of thyme with one part of oil of cloves. 

 (Is not white oil of thyme identical with origanum oil ?) 



Some specimens of clove oil dissolve collodion very slowly, and may be 

 used, but I would not be understood to recommend it. Tbe action of origanum 

 oil varies much, according to the samples ; some sorts do not clear the collo- 

 dion, others dissolve it, others pucker it. MINOT (Zeit. f. wiss. Mile., iii, 2, 



1886, p. 175) says that Dunham's mixture " clarifies the sections very readily 

 and softens the celloidin just enough to prevent the puckering, which is so 

 annoying with thyme alone." 



Carbolic acid has been recommended. WEIGEET (Zeit.f. wiss. Mile., iii, 

 4, 1886, p. 480) finds that a mixture of 3 parts of xylol with 1 part of 

 carbolic acid (anhydrous) clears well. But it must not be used with the 

 basic anilin stains, as it discolours them. For these, anilin oil may be used 

 with the xylol, in the place of carbolic acid. 



Anilin oil clears well, but unless thoroughly removed the preparation 

 becomes yellowish-brown (see VAN GIBSON, Amer. Mon. Mic. Journ., 



1887, p. 49, or Journ. Roy. Mic. Soc., 1887, p. 519, for a review of these 

 clearing agents). 



Beechwood kreasote has been recommended (by M. Flesch). 



299. Double Imbedding in Collodion and Paraffin. The best- 

 hardened collodion masses are of a more elastic consistency 

 than is desirable for fine section cutting. This defect may be 

 to a certain extent remedied as follows : Dip the block of 

 hardened collodion into chloroform, and imbed it simply in 

 paraffin. 



Kultschizky's Celloidin-Paraffin Method. A more thorough- 

 going procedure is the following infiltration method (Zeit.f. 

 wiss. Mik., iv, 1, 1887, p. 48) -.After the collodion bath, the 



