FIXING AND PRESERVATIVE MEDIUMS 41 



This is specially indicated by Lo Bianco as a fixative for 

 Callianira, one of the Ctenophora, unless fixed by the chrom- 

 osmic mixture (Formula 39). 



21. — Bichloride of Mercury and Sulphate of Copper"(Lo Bianco, p. 443) 



Bichloride of mercUry (saturated solution) . .10 parts 



Sulphate of copper (10 per cent, solution) . 100 „ 



Such Hydromedusae as Eucope, Gasiroblasta, and Obelia 

 are fixed by the above, and after two minutes they should be 

 washed in fresh water until all trace of the precipitate has dis- 

 appeared. 



Amongst the "worms," the Chaetognatha are nicely fixed 

 also by this reagent. 



22.^"Goadhy's Fluids {Micro. Did., art. 'Preservation') 

 " 1st Fluid — 



Bay salt (coarse sea-salt) 4 oz. 



Alum ... . . 2 „ 



Corrosive sublimate . . 3 grains 



Boiling vi^ater . . . . . i quart 



" This is found to be ' too strong ' for most purposes, and 

 therefore the following is recommended for general purposes : — 



23.— 



" 27td Fluid — 



Bay salt . 4 oz. 



Alum ... 2 „ 



Corrosive sublimate . . 4 grains 



Water . ... 2 quarts 



" ' Schultze recommends it for preserving Medusce, Echino- 

 dermata, Annelid larvse, Entomostraca, Polythalamia, and Poly- 

 cystina, and advises the use of glycerin afterwards to produce 

 transparence.' " ^ 



It is said that, where carbonate of lime is found in the 



^ Microtomist' s Vade-mecum, pp. 238, 239. 



