44 



CHAPTER XXXIF 



FIXATIVES*' 



1. Flemmings Solution. 



Chromic acid, I per cent. - 15 vols. 



Osmic acid, 2 per cent. - 4 vols. 



Glacial acetic acid i vol. 



Mix in the above proportions before use. Use 

 very small pieces of tissue. Fixation is complete in 

 about twenty-four hours. Wash well in water, and 

 transfer gradually to eighty per cent, alcohol. 



2. Sublimate-alcohol. 



Saturated watery solution of corrosive 



sublimate - 2 parts. 



Absolute alcohol - I part. 



Fix small pieces for two or three hours more or 

 less according to size. Transfer to eighty per cent, 

 alcohol. Wash out the sublimate from the sections 

 with Lugol's solution. Faeces containing Amoebae can 

 be preserved by shaking up in this fixative and pre- 

 serving in tubes. 



3. Acetic Alcohol. 



Glacial acetic acid I part. 



Absolute alcohol 3 parts. 



Penetrates and fixes rapidly, according to the size 

 of the tissue. It should be used where chitinous 

 structures exist. Wash out the acid in alcohol. 



*For diagnostic purposes dried smear preparations are of great value, but for 

 studying the parasite in its relation to the tissues, e.g. in Leishmania donovani or 

 Histoplasma capsulata, or in malaria, it is necessary to cut sections, and for this 

 purpose the tissues must have been carefully prepared previously. 



