SOHALLIBAUM'S COLLODION. 173 



This simple process is very useful for the preliminary ex- 

 amination of trial sections whilst cutting. It is often suffi- 

 cient to put on a cover, warm, withdraw the melted paraffin" 

 by means of a cigarette paper, and run in a drop of clearing 

 agent. 



315. Schallibaum's Collodion (Arch. f. mik. Anat., 1883, p. 

 565). One part of collodion is shaken up with three to four 

 volumes (according to the consistency of the collodion) of 

 clove oil or lavender oil. This should give a clear solution. 

 A little is spread thinly on a slide with a small brush. After 

 arranging the sections on the prepared surface, warm over a 

 water-bath, gently, until the clove oil has evaporated (five to 

 ten minutes). The sections are then found to be fixed, and 

 can be treated for days with turpentine, chloroform, alcohol, 

 and watery fluids, without becoming detached. The advan- 

 tage of this method is, that it allows of staining on the slide. 

 If after staining any cloudiness should appear between the 

 sections, dehydrate the slide and treat it several times with 

 absolute alcohol and turpentine, warming it gently the while ; 

 or brush the space between the sections repeatedly with a 

 brush moistened with clove oil. This cloudiness only arises 

 from the collodion solution having been taken too concentrated, 

 or having been laid on too thick on the slide. 



I find it is not necessary to evaporate over a water-bath. 

 It is sufficient to hold the slide over a spirit-lamp until the 

 paraffin has melted and the clove oil has collected in drops 

 between the sections. Schallibauin has stated elsewhere that 

 long evaporation of the slide is necessary if the sections are 

 to be secured firmly enough to allow of staining on the slide. 

 That is not so. What is necessary is that the paraffin and 

 clove oil be thoroughly removed from contact with the sec- 

 tions ; and that can be done in a second (as was shown me by 

 Professor v. Korotueff). Warm the slide over a flame, and 

 whilst the paraffin is still melted hold it close before your lips 

 and blow down on it vigorously. The paraffin and clove oil 

 are scattered right and left over the slide, leaving the sections 

 high and dry. 



Personally, I do not consider Schallibaum's method so safe 

 as Mayer's albumen (and some other methods) for objects 

 that are to be stained on the slide. I recommend it for 



