METALLIC STAlIsrS (IMPREGNATION METHODS). 217 



X>ath. Anat., xix, p. 451). Physiological salt solution (0-75 

 per cent.) is commonly used for these washings. 



MuLLKE {Arch. f. joath. Anat., xxxi, p. 110), after impreg- 

 nation by immersion for two or three minutes in a 1 per cent, 

 solution of nitrate of silver in the dark, adds to the solution 

 a small quantity of 1 per cent, solution of iodide of silver 

 (dissolved by the aid of a little iodide of potassium). After 

 being agitated in this mixture the preparations are washed 

 with distilled water, and exposed to the light for two days 

 in a 1 per cent, solution of nitrate of silver (see also Gierke, 

 in Zeit. triss. MiJi., i, 1884, p. 396). 



RonGET {Arch, de Physiol., 1873, p. 603) reduces in 

 glycerin; SziJTZ {Zeit.,wiss. Mik., xxix, 1912, p. 291) in 

 glycerin with y'„ of formol. 



Sattlek {Arch. Mih. Anat , xxi, p. 672) exposes to the 

 light for a few minutes in water acidulated with acetic or 

 formic acid. Thanhoppee {Das Mikroskoji, 1880) employs a 

 2 per cent, solution of acetic acid. 



Keauss brings his preparations, after washing, into a light 

 red solution of permanganate of potash. Reduction takes 

 place very quickly, even in the dark. 



Oppitz puts for two or three minutes into a 0'25 or 0"50 

 per cent, solution of chloride of tin. 



Jakimovitch {Juurn. de I'Anat., xxiii, 1888, p. 142) brings 

 nerve preparations, as soon as they have become of a dark 

 brown colour, into a mixture of formic acid 1 part, amyl 

 alcohol 1 part, and water 100 parts, and exposes to the 

 light for five to seven days, the mixture being renewed 

 from time to time. 



Dekhuysen {of. cit., last §) reduces in oil of cloves, after 

 dehydration. 



355. Fixation. — Legeos (/oto'tc. de l' Anat. ,1868, p. 275) washes Lis 

 preparations, after reduction, in hyposulphite of soda, to prevent after- 

 blackening. According to Dtjval {I'recis, p. 230) they should be washed 

 for a few seconds only in 2 per cent, solution and then in distilled 

 water. 



Gbbota (Arch. Anat. Fhys., Phys. Ahth., 1897, p. 428) reduces in a 

 bydroquinone developing solution, followed by fixation in h3'posulphite 

 of soda, just as in photography. 



356. Impregnation of Marine Animals. — On account of the 



