THE EHELICH-BIONDI MIXTURE. 161 



matic spindle-fibrils grey to grey-brown, or, in very favorable 

 cases, violet, and are very clearly brought out ; attractive 

 spheres, centrosomes, polar corpuscles, and "Zwischen- 

 korper" reddish in light stains, brown- violet to black-brown 

 in strong ones. 



Lists of some colours that give good results as primary and 

 as secondary stains are given in 98. Besides the combina 1 

 tions there recommended I would particularly recommend 

 that of Gentian Violet and Eosin. Stain and wash out (not 

 too far) by Bizzozero's method ( 102), and then stain for a 

 few seconds, or as much as two to five minutes, in fairly strong 

 aqueous solution of eosin, dehydrate rapidly with alcohol, 

 clear, and mount ; or Benzopurpurin may be taken instead of 

 eosin (see 133). 



Attention should be paid to the decolourising action of the 

 secondary stain on the primary (see 98). This reaction may 

 be utilised, as proposed by BAUMGAETEN (infra, 268). RE- 

 SEGOTTI (Zeit. f. wiss. Mile., v, 3, 1888, p. 323) recommendrs 

 staining for five minutes (this is for tissues fixed by alcohol) 

 in strong solution of Methyl Violet or Dahlia, then washing out 

 for one or two minutes in very weak solution of (alcoholic) 

 Eosin or of Saurefuchsin in alcohol, then dehydrating and 

 clearing. 



In the following paragraphs are given some other methods 

 of proved utility. 



259. The EHELICH-BIONDI Mixture (or EHELICH-BIONDI-HEI- 

 DENHAIN Mixture) (Pfluger's Arch., xlii, 1888, p. 1; Zeit. f. 

 wiss. Mik., v, 4, 1888, p. 520). This well-known stain is 

 somewhat troublesome to prepare. It may be obtained ready 

 made from Dr. GEUBLEE (12, Baiersche Strasse, Leipzig). 



The receipt is as follows : To 100 c.c. saturated aqueous 

 solution of Orange add with continual agitation 20 c.c. satu- 

 rated aqueous solution of Saurefuchsin (Acid Fuchsin) and 

 50 c.c. of a like solution of Methyl Green. 



Dilute the mixture with 60 to 100 volumes of water. The 

 dilute solution ought to redden if acetic acid be added to it ; 

 and if a drop be placed on blotting-paper it should form a 

 spot bluish green in the centre, orange at the periphery. If 

 the orange zone is surrounded by a broader red zone, the 

 mixture contains too much fuchsin. 



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