64 CHAPTER V. 



The addition of chloroform is said to render the action of 

 the mixture more rapid, 



V. BENEDKN and NKYT take equal volumes of glacial acid 

 and absolute alcohol. 



ZACHAKIAS takes 



Glacial acetic acid . . .1 part. 



Absolute alcohol . . .4 parts. 



Osmic acid . . . .a few drops. 



Acetic alcohol is one of the most penetrating and quickly 

 acting fixatives known. It preserves both nuclei and cyto- 

 plasm, and admits of admirable staining in any way that may 

 be preferred. It was employed by all of the authors quoted 

 for the study of karyokinesis in the ova of Ascaris pro- 

 verbially one of the most difficult objects to fix, but from 

 what I have seen of it I should say that it is applicable with 

 advantage to many other objects, and has been found to give 

 excellent results with central nervous tissue. You may wash 

 out with alcohol and treat afterwards in any way that may be 

 preferred (aqueous liquids being avoided as far as possible) . 

 But the sublimate liquid, next , will probably be found in 

 many cases superior. 



84. Acetic Alcohol with Sublimate. The following mixture 

 due to G-ILSON, was first published by CARNOY and LHJBRDN 

 (La Cellule, xiii, 1, 1837, p. 68), and most highly recom- 

 mended by them as superior for ova of Ascaris with the 

 shell formed to the chloroform liquid of the last . The 

 addition of the sublimate serves to restrain the swelling 

 action of the acetic acid, which is insufficiently done by the 

 other ingredients. 



Absolute alcohol . . . .1 vol. 



Glacial acetic acid . . . 1 



Chloroform . . . . . . 1 



Sublimate to saturation. 



Isolated ova of Ascaris, even though furnished with a 

 shell, are fixed in twenty-five to thirty seconds. Entire 

 oviducts take about ten minutes. The liquid is therefore 

 one of the most penetrating and rapidly acting of any, if not 

 the most. 



Wash out with alcohol until all traces of odour of the 

 acetic acid have disappeared (I myself wash out with alcohol 



