592 SUMMARY OF CURRENT RESEARCHES RELATING TO 



alcohol, and then adding 870 of distilled water and 20 of glacial acetic 

 acid. This solution must stand uncovered in the light for 3 weeks 

 before use. The sections are stained for 20 hours at a temperature of 

 30° C. On removal the sections are treated for 10 minutes with a 

 saturated solution of lithium carbonate, and are then washed with dis- 

 tilled water until the water runs off quite clear. The sections are now 

 decolorised after Pal's method, though the permanganate solution is 

 stronger. In solution A (pot. permang. 5, H 2 1000) the sections 

 remain 1 minute ; in B (acid, oxalic. 5, pot. sulphurosum 5, H 2 1000) 

 5 minutes. If not sufficiently decolorised, the whole business must 

 be gone through again. 



The decolorised sections are next washed and treated successively 

 with methyl-alcohol, creosote and carbolxylol. In each of these fluids 

 they remain 5 minutes, after which they are mounted in balsam. 



If it be desired to double-stain the sections, this may be done with 

 magdala red, congo red, or fuchsin ; but the preference is given to the 

 following : Rubin 1, H 2 200, glacial acetic acid 4. The counter- 

 staining must be done after differentiation in B solution and washing 

 in water. It takes about 3 hours, after which the sections are immersed 

 for 24 hours in 2 p.c. acetic acid. 



Modification of the Van Gieson Method.* — K. "VYeigert recom- 

 mends the following improvement of the Van Gieson method. For 

 alum-hajmatoxylin is substituted iron-hamiatoxylin. This is prepared 

 by mixing, when required for use, equal parts of two solutions : A, con- 

 sisting of 1 grm. hematoxylin to 100 c.cm. of 9G p.c. alcohol ; B, of 

 4 c.cm. liq. ferri sesqnichlorati, 1 c.cm. of hydrochloric acid, and 95 

 water. The iron chloride solution contains 10 p.c. iron ; the specific 

 gravity of HC1 is 1 ■ 124, ' German Pharmacopoeia.' 



The acid fuchsin-picric acid mixture is made by adding 10 parts of 

 1 p.c. aqueous solution of acid fuchsin to 100 parts of saturated aqueous 

 solution of picric acid. 



The sections previously stained with iron-hamiatoxylin are placed 

 in the picric-fuchsin solution for only 'a short time ; they are then 

 quickly washed in water, dehydrated in 90 p.c. alcohol, and cleared up 

 in carbolxylol. 



Method of Staining" Sections Quickly with Picrocarmin.t — "W. 

 Freeman gives the following method by which staining with picro- 

 carmin is complete in a few minutes. The staining is almost entirely 

 that of carmin, but the picric acid can be easily added by passing the 

 sections through alcohol tinged with picric acid in the usual way for 

 successive double stains. The fixatives used were Midler's fluid, potas- 

 sium bichromate, Weigert's chrome-alum mixture and formalin, with 

 after-hardening in alcohol. The picrocarmins used were Bourne's and 

 H oyer's. (1) To 1 volume of Bourne's picrocarmin 9 volumes of 

 • 2 p.c. acetic acid are added ; the mixture is filtered preferably after 

 boiling. The sections cut with a freezing microtome are placed in the 

 dilute picrocarmin, which is then heated quickly just to the boiling- 



* Zeitschr. wiss. Mikr., xxi. (1904) pp. 1-5. 



t Proc. Physiol. Soc, May 1903 ; Journ. Physiol., xxix. (1903) pp. xxx-i. 



