124 CHAPTER X. 



191. OBREGIA'S Method for Paraffin or C3lloidiu S actions 

 (Neurologisches Centralb., ix, 1890, p. 295 ; G-ULLAND, Jo urn. 

 of Path., February, 1893). Slides, or glass plates of any 

 size, are coated with a solution made of 



Syrupy solution of powdered candy- 

 sugar made with boiling distilled 

 water . . . . .30 c.c. 



95 per cent, alcohol . . . 20 



Transparent syrupy solution of pure 

 dextrin made by boiling with dis- 

 tilled water . . . . 10 

 They are dried slowly for two or three days until the 

 surface is just sticky to the moist finger. Paraffin sections 

 are arranged and heated for a few minutes to a temperature 

 slightly above the melting-point of the paraffin. The paraffin 

 is removed by some solvent, and this in turn by absolute 

 alcohol. The alcohol is poured off, and the sections are 

 covered with solution of celloidin. The plates are left to 

 evaporate for ten minutes in a horizontal position, then 

 brought into water, in which the sheet of celloidin with the 

 sections soon becomes detached, and may be further treated 

 as desired, e. y. as in Weigert's process, 198. The evapo- 

 ration must not be artificially hastened. 



DIMMER (Zdt. wits. Mile., xvi, 1899, p. 44) coats the slides with a 

 solution of about 16 parts of gelatin in 300 of warm water, and dries 

 them (two days), and proceeds in other respects as above. 



A good method for large sections, equally applicable to 

 paraffin sections, to celloidin sections, and to sections of 

 material that has not been imbedded at all. 



For BLOCHMAN'S modification of Weigert's process, by means of 

 which large sections can be preserved unmounted, see Zeit. wiss. Mik., 

 xiv, 1897, p. 189. 



192. STRASSER'S Collodion Paper Method (ibid., iii, 188G, p. 346).- 

 This is an extremely coni|>lir;iU'd modification of Weigert's method for 

 celloidin sections, and is only adapted for use with STRASSER'S automatic 

 ribbon-microtome. See Zdt. ivies. Mik., iii, 1886, p. 346 ; vi, 1889, p. 154 ; 

 vii, I S'.HI, pp. ii:o ai.d 3<l ; ix. INJJJ, p. y ; x ii, 1895, p. 154 ; and xiv, 1897, 

 p. 3:> ; also SCHOENKMANN, Hu'd.. xix, 1903, p. 333; STRASSER, ibid., 

 p. 337 ; and RUIM-KICHT. ////./., xxviii. TJ12. p. 281. 



