220 EXAMINATION AND PRESERVATION MEDIA 



448. Acetate of Potash (Max Schultze, Arch, mik. Anat., vii, 1872, 

 p. 180). A nearly saturated solution in water. The index of refraction 

 is lower than that of glycerin. 



449. Syrup. A good strength is equal parts of loaf sugar and water. 

 Dissolve by boiling. To preserve it from mould, chloral hydrate may 

 be dissolved in it (1 to 5 per cent.) — Lee has used as much as 7 per cent., 

 and found no disadvantage — or carbolic acid (1 per cent.). 



It may be used as a mounting medium, but there is always risk of the 

 sugar crystallising out. 



Fabre-Domergue {Bull. Soc. Philomath., ix, 1899, p. 115) dissolves 

 200 parts of sugar in 400 of water, and adds 1 part of formaldehyde, and 

 camphor to saturation. 



450. Chloral Hydrate. Five per cent, in water (Ladowsky, 

 Arch.f. mik. Anat., 1876, p. 359). 



Or, 2-5 per cent, in water (Brady, British Copepods). 

 Or, 1 per cent, in water (Munson, Journ. Roy. Mic. Soc, 1881, 

 p. 847). 



MERCURIAL LIQUIDS 



{Lee gave these as examination media only, not as permanent mounting 

 media. Media containing sublimate always end by making tissides 

 granular.) 



451. Gilson's Fluid (Carnoy's Biologic Cellulaire, p. 94). 



Alcohol of 60 per cent. . . . .60 c.c. 



Water 30 „ 



Glycerin . . . . . . 30 ,, 



Acetic acid (15 parts of the glacial to 85 of 



water) . . . . . . 2 ,, 



Bichloride of mercury .... 0-15 grm. 



452. Gage's Albumen Fluid {Zeit. f. iviss. Mik., 1886, p. 223). 



White of egg . . . . . .15 c.c. 



Water 200 „ 



Corrosive sublimate. .... 0-5 grm. 



Salt ....... 4 ,, 



Mix, agitate, filter, and preserve in a cool place. Recommended for 

 the study of red blood-corpuscles and ciliated cells. 



453. Pasini's Fluids {Journ. de Mik., iv, 1880 ; Journ. Roy. Mic. Soc, 

 [N.S.] ii, 1882, p. 702, and early editions of this work). Antiquated and 

 superfluous. They consist essentially of corrosive sublimate of from ^ 

 to I per cent, strength, with the addition of a little salt or acetic acid. 



454. Goadby's Fluids {Micro. Diet., art. " Preservation," or early 

 editions of this work). Quite unsuited for histological purposes. 



OTHER FLUIDS* 



455. Chloride and Acetate of Copper (Ripart et Petit's fluid, 

 see § 95). 



* For Berlese's gum chloral, see § 1188. This is an important medium 

 because it does not contain glycerin, which attacks certain metallic 

 impregnations, and which is the " active " constituent of most of these 

 aqueous gum media. Notice that in all cases the gum should first be 

 dissolved in the water, the other constituents being added later to the 

 filtered liquid. 



