CHLORIDES ORGANIC ACIDS ETC. 



45 



Gilson's Mixture (Gilson, in litt., 1895). 



Nitric acid of sp. gr. 1*456, or 80 per 



cent., nearly) . 

 Glacial acetic acid 

 Corrosive sublimate 

 60 per cent, alcohol 

 Distilled water . 



15 c.c. 

 4 



20 grm. 

 100 c.c. 

 880 „ 



When required /or marine animals add a few crystals of iodine, which 

 will prevent the formation of precipitates of sea salts. If in any case 

 the preparations should show a granular precipitate, this may be 

 removed by washing with water containing a httle tincture of iodine. 



We find that it affords in general a faithful and delicate fixation, 

 and gives to tissues an excellent consistency. Objects may remain 

 in it for a considerable time without hurt. It has a high degree of 

 penetration. A treatment for a few days with it will serve to remove 

 the albumen from the ova of Batrachians. This liquid may be recom- 

 mended to beginners, as it is very easy to work with. For some objects, 

 the proportion of sublimate may be increased with advantage. 



KosTANECKi and Siedlecki (Arch. mik. Anat., cxliii, 1896, p. 181) 

 take a mixture of saturated sublimate solution and 3 per cent, nitric 

 acid in equal parts, or a mixture of equal parts of sublimate solution, 

 3 per cent, nitric acid, and absolute alcohol, fix for twenty-four hours, 

 and wash out in iodine-alcohol. 



Petrunkewitsch {Zool. Jahrb. Abth. Morph., xiv, 1901, p. 576) 

 takes water 300, absolute alcohol 200, glacial acetic acid 90, nitric 

 acid 10, and sublimate to saturation. Both this and Gilson's have 

 been much used lately. 



75. Picro-sublimate Mixtures. Rabl's {Zeit. wiss. Mik., xi, 

 1894, p. 165). Sublimate, saturated solution in water, 1 vol. ; 

 a similar solution of picric acid, 1 vol. ; distilled water, 2 vols. 

 Embryos may be left in it for twelve hours, washed for two hours 

 in water, and brought into weak alcohol. 



O. VOM Rath [Anat. Anz., xi, 1895, p. 268) takes cold saturated 

 solution of picric acid, 1 part ; hot saturated solution of sublimate. 

 1 part ; glacial acetic acid, J to 1 per cent. Also the same with the 

 addition of 10 per cent, of 2 per cent, osmic acid solution. 



76. Osmio-sublimate Mixtures. Mann's {Zeit. iviss. Mik., xi, 

 1894, p. 481) consists of a freshly prepared mixture of equal parts 

 of 1 per cent, osmic acid solution and saturated solution of sub- 

 limate in normal salt solution. This solution has been much used 

 in recent years for fixation before osmication and is a splendid 

 fixative (see §§ 710 et seq.). 



77. Chromo-sublimate. Lo Bianco {Mitth. Zool. Stat. Neapel, 

 ix, 3, 1890, p. 443). Concentrated sublimate solution, 100 parts ; 

 1 per cent, chromic acid, 50 parts. 



Mann {Verb. Anat. Ges., 12, 1898, p. 39) takes for nerve-cells equal 

 parts of 5 per cent, sublimate and 5 per cent, chromic acid. 



