XIX 



about eighty per cent, for preserving. After the use of other 

 fixatives, specimens should be washed and transferred to eighty 

 per cent, oj:' alcohol for preservation. 



Rectified spirit of the British Pharmacopaeia, is equal to 

 eighty-four per cent, alcohol. 



Methylated spirit, containing wood naptha, is equal to 

 ninety per cent, alcohol. 



Ordinary methylated spirit contains mineral naphtha, and 

 should not be used. 



Absolute alcohol is equal to ninety-eight per cent, alcohol. 

 For practical purposes the dilution of alcohols is sufficiently 

 ' accurately made by means of the diluting formula (p. xvii). 



Zenker'' s Fluid : — 



Potassium Bichromate 2-5 grammes 



Sodium Sulphate I'o grammes 



Corrosive Sublimate 5'o grammes 



Water loo'o grammes 



Add glacial acetic acid to this stock solution, in the pro- 

 portion of five grammes to one hundred c.c, before use. Fixa- 

 tion is complete in one to twenty-four hours. Wash thoroughly 

 in alcohol to which enough iodine has been added to give a 

 dark-brown solution. Or, if alcohol is undesirable, use tinc- 

 ture of iodine, two parts, potassium iodide, one part, glycerine, 

 fifty parts, water, fifty parts. Renew until no further decoloura- 

 ' tion takes place. 



Haematin or eosin and methylene blue give good results 

 for malarial tissues. 



Orth's Fluid. — This is MuUer's fluid, to which formalin 

 {i.e., formaldehyde forty per cent, solution) is added in the pro- 

 portion of ten c.c. to one hundred c.c. of Muller before use. 



Fixation of small pieces takes plage in two to three hours, 

 if kept warm. Wash thoroughly. Pass through alcohol. 



MuUer's Fluid. — Potassiifm Bichromate, 2^ parts. 

 Sodium Sulphate i part. 



Water 100 p4rts. 



Add a little camphor or naphthalin to prevent the growth 



of moulds. Change the fluid after twenty-four hours, and then 



every few days for the first week. Tissues are ready in a fort- 



\ night or three weeks. They may be left much longer. Fix 



