254 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(4) Staining: and Injecting-. 



Staining Dysenteric Amoebae.* — Dr. S. Amberg bases tbe diagnosis 

 of amoebic dysentery on tbe finding of motile amoebae containing red 

 corpuscles in tbe stools. A suitable piece of material is stained with 

 aqueous solution of toluidin-blue, or witb methylen-blue and neutral 

 red. Tbe two la^t may be used in aqueous solution or in substance. 

 Witb neutral red tbe erythrocytes are at first of a brassy colour, and 

 finally red. The results with methylen-blue were very similar. Tbe 

 methods are only successful with living amoebae, and tbe staining fades 

 out in a few hours. Attempts to preserve the specimens were unsuccess- 

 ful. The presence of Charcot-Leyden crystals and eosinophilous cells 

 in the faeces was almost constant. 



Iron Impregnation of Nerve Fibrillae. f — Dr. S. Meyer gives the 

 following method for impregnating nerve fibrillae with iron. Pieces of 

 moderate size are fixed for 24 hours in 10 p.c. formalin solution. They 

 are then transferred for 8-20 days to 2^ p.c. ferrocyanide of potassium, 

 followed by 10 p.p. iron-alum for 2-4 days, after which they are washed 

 for some hours. The subsequent treatment is absolute alcohol 2 days, 

 xylol 2 hours, paraffin 2-4 hours. The sections, 10-60 fi, are stuck on 

 with alhumen-glycerin ; xylol, balsam. By this the fibrillae are better 

 stained than by other procedures, and it also has the advantage of not 

 depositing a granular or crystalline precipitate among the stained 

 elements. 



Staining Nerve-Fibrillae of Neurones in Electric Lobes4 — Sbin- 

 kiski Hatai fixed the material in 10 p.c. formalin. Then a thin piece 

 was cut from tbe electric lobe of Torpedo occidentalis and immersed in 

 distilled water for about six hours. The material was then removed to 

 35 p.c. alcohol for about an hour, after which it was carried through 

 graded alcohols and imbedded in paraffin. Tbe sections, about 12 /x 

 thick, were stained with saturated aqueous solution of toluidin-blue and 

 contrast-stained with alcoholic solution of erytbrosin. By this pro- 

 cedure the fibrillar arrangement of tbe cytoplasm was shown. 



New Method of Examining Sputum.§ — Dr. U. Quensel mixes the 

 sputum to be examined with an equal bulk (or more) of a mixture com- 

 posed of 1 vol. 25 p.c. formalin and 1 vol. 95 p.c. alcohol. The 

 mixture is shaken up vigorously for 1 or 2 minutes, and is then allowed 

 to sediment or is centril'uged. A small drop of the sediment is then 

 squeezed out between the cover-glasses and the films dried in the air. 

 They may be fixed in the flame, but this step is unnecessary. 



The films may be stained witb carbol-fuchsin, thougb tbe author 

 prefers anilin-water gentian-violet, and after decolorising, contrast-stains 

 with vesuvin or witb an aqueous solution of auramin. Instead of the 

 gentian-violet solution, which is somewhat unstable, tbe following is 

 recommended as it keeps better : — One vol. of saturated solution of 

 crystal violet in 70 p.c. alcobol, 1 vol. of 1 p.c. solution of hydro- 

 chloric acid in 70 p.c. alcobol, and 2 vols, anilin-oil-water. 



* Johns Hopkins Hosp. Bull., xii. (1901) pp. 355-63. 



t Anat. Anzeig., xx. (1902) pp. 535-43. 



j Journ. Cincinnati Soc. Nat. Hist., xx. (1901) pp. 1-12 (1 pi.). 



§ Nord. Med. Arkiv, Afd. ii. xxxiv. (1901) No. 22, pp. 1-3. 



