212 SERIAL SECTION MOUNTING. 



the degree of adhesion seems to depend very much on the 

 nature of the sections. 



SCHIEFFERDECKER (Zeit. f. wiss. Mik., ix, 2, 1892, p. 202) 

 finds that the larger and thinner sections are, the better do 

 they stick, and vice versa. And Mr. ANDREW PRINGLE writes 

 me that he finds that tissues thoroughly fixed in chrome solu- 

 tions, so that their albuminoid substances have become quite 

 insoluble, do not adhere sufficiently without the aid of some 

 substance to fix them to the slide. He prefers arranging 

 sections on the slide with cold water, and then warming until 

 the sections flatten out. 



HEIDENHAIN (" Feschr. Herrn. v. Kolliker gewidm.," &c., 

 1892; see Zeit.f. wiss. Mik., ix, 2, 1892, p. 201) also proceeds 

 in this way, and advises that the heating be not carried to 

 above 35 C., at which temperature several hours at least are 

 necessary to ensure fixation. He also finds that water is pre- 

 ferable to alcohol, which is too mobile on the slide and eva- 

 porates too quickly. DURHAM'S method (Quart. Journ. Mic. 

 8ci., xxxiii, 1891, p. 116; Journ. Roy. Mic. 8oc., 1892, p. 293) 

 is the same as the last described, with the exception that he 

 uses 70 per cent, alcohol instead of water. 



325. Schallibaum's Collodion Method (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 too thick on the slide. 



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



