DOUBLE IMBEDDING IN COLLODION AND PARAFFIN. 203 



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 (it will clear from 70 per cent, alcohol), but unless 

 thoroughly removed the preparation becomes yellowish brown. It may be 

 removed by soaking in chloroform for twenty-four hours (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 ; see also 353). 



Beech wood kreasote has been recommended (by M. Flesch). 



EYCLESHEIMEE (Amer. Nat., xxvi, 1892, p. 354 ; Journ. Soy. Mic. Soc., 

 1892, p. 565) advises a mixture of equal parts of bergamot oil, cedar oil, and 

 carbolic acid. 



306. 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 

 object is soaked in oil of origanum (Oleum Origani vulg.). It 

 is then brought into a mixture of origanum oil and paraffin, 

 heated to not more than 40 C., and lastly into a bath of pure 

 paraffin. 



The mass may be preserved in the dry state, and may be 

 cut dry. 



RYDER (Queen's Micr. Bull., 1887, p. 43; Journ. Roy. Mic. 

 Soc., 1888, p. 512) has modified the process by substituting 

 chloroform for the origanum oil. He states that sections 

 chain more easily than even in ordinary paraffin imbedding. 

 They may be cleared for mounting either with chloroform or 

 with Weigert's xylol and carbolic acid mixture (supra, 305 ; 

 Ryder says "equal parts," but Weigert's formula is as above 

 given). 



IDE (La Cellule, vii, 1891, p. 347 ; see also Zeit. f. wiss. 

 Mik., ix, 2, 1892, p. 213) has employed with success the 

 following method : The object is imbedded in collodion in a 

 tube by GILSON'S process (supra, 301) ; the collodion is 

 boiled for forty minutes, then brought for fifteen minutes 

 (this is for small objects) into chloroform heated to 30 C. 

 containing one fourth part of paraffin dissolved in it, then for 

 ten minutes into pure melted paraffin. 



