368 METHODS. 



stand twenty-four hours ; filter. Borax carmine gives a good nuclear stain and 

 may be advantageously supplemented by counterstains. 



For in toto staining place the specimen in water until it sinks ; transfer to the 

 carmine for twenty-four hours, or longer for large specimens ; wash in water for 

 five minutes; then place it in 70 per cent, alcohol, to every 100 c.c. of which 2 c.c. 

 of hydrochloric acid have been added; after one hour transfer to fresh 70 per 

 cent, alcohol, which must be renewed in an hour or two, and finally transfer to 

 80 per cent, and 95 per cent, alcohol, and the specimen will be ready to imbed. 



3. COUNTERSTAINS are used either with celloidin sections treated singly, or 

 with paraffin sections after they have been fastened on the slide. The three here 

 recommended are alcoholic solutions, and the method of using is the same for all. 



For staining paraffin sections on the slide it is convenient to have eight jars 

 or dishes large enough to hold a slide. The slide is transferred from jar to jar in 

 the order below, being allowed to remain in each jar a few minutes. The very 

 most scrupulous care is necessary to keep all the fluids clean, and it is indispensable 

 to filter them frequently; the sections on the slide" catch and hold the particles 

 floating in the reagents when they are not clean. 



Order of jars: i. Xylol. 



2. Xylol. 



3. Xylol and absolute alcohol, equal parts. 



4. Absolute alcohol. 



5. Counterstain. 



6. Alcohol of 95 per cent. 



7. Absolute alcohol. 



8. Xylol. 



Eosin Formula: 2 per cent, in 95 per cent, alcohol. 



Orange G formula: l per cent, in 95 per cent, alcohol. 

 Lyons blue Formula; I per cent, in 95 per cent, alcohol. 



4. HEIDENHAIN'S IRON HEMATOXYUN. 



Formula I : Iron alum, 2 gm. 



Distilled water, looc.c. 



II : Hematoxylin crystals, I gm. 



95 per cent, alcohol, 10 c.c. 



Distilled water, 90 c.c. 



1. Place sections in the iron solution for thirty to sixty minutes. (Speci- 

 mens hardened with Flemming's or Hermann's fluid require longer than speci- 

 mens from Zenker's or Tellyesnicky's fluid.) 



2. Wash quickly in water. 



