714 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the film is stained with carbol-fuchsin or with anilin-oil-gentian-violet 

 or fuchsin. The cover-slip should lie in the boiling stain for at least 

 one minute. Thou wash, and run on the following solution : — Ammo- 

 nium persulphate 5 grin. ; alcohol 95 p.c, 50 ccm. ; H 2 0, 10 ccm. At 

 the end of half a minute wash and counter-stain. The preparation will 

 show red or violet spores and bacilli coloured with the contrast stain. 

 Sputum may be stained by the foregoing method, but if pushed too far 

 the tubercle bacilli may be decolorised. 



New Staining Method.* — Dr. A. Spuler has devised the following 

 procedure. Finely-powdered cochineal is boiled with distilled water, 

 filtered, and evaporated nearly to dryness. Alcohol is then added, and 

 the mixture filtered and evaporated down. The residue is dissolved in 

 distilled water, and the solution filtered. Pieces of tissue which have 

 been fixed in the usual way are immersed in this staining solution and 

 incubated for 24 hours. On removal they are washed and then mordanted 

 in dilute iron-alum solution. After having been thoroughly washed 

 they are imbedded and sectioned. The sections present pictures like 

 pen-and-ink drawings, the nuclei and cell contours being extremely well 

 stained. 



Modification of Gram's Method.f — Dr. C. Kisskalt shows that by 

 using amyl-alcohol most bacteria can be stained by Gram's method, the 

 exceptions being Bacterium vulgare, Bacillus pyocyaneus, and three 

 vibrios, V. choleras, V. Metchnikovi, and V. albensis. In all thirty-nine 

 bacteria were tested, and the results are given in a table, at one end of 

 which stands methyl-alcohol followed by ethyl, propyl, butyl, and amyl, 

 in the order given. 



Modification of Hoyer's Thionin Stain.} — Dr. P. Hari's modifica- 

 tion of Hoyer's staining for mucus is carried out in the following way. 

 From the sections, which are all prepared from the celloidin method, 

 all the celloidin must be completely removed by means of ether and 

 ether-alcohol. The ether is extracted by treatment with absolute 

 alcohol for 5 minutes. The sections are then washed in water for 

 3 minutes, after which they are immersed for 10-12 minutes in the 

 sublimate solution used for fixing the material (sublimate 7, salt 0*5, 

 water 100). The sections are next washed in absolute alcohol for about 

 half a minute, and for a similar time in water, after which they are 

 transferred to a freshly filtered 1 p.c. aqueous solution of thionin for 

 3-4 minutes. The over-stained sections are washed in water until the 

 dye is no longer given off, and are then immersed in absolute alcohol for 

 a similar object. The sections are then further decolorised in a mixture 

 of equal parts of oil of cloves and carbol-xylol (acid carbol 1, xylol 2). 

 In rather less than a minute the sections are placed on a slide and ex- 

 amined under a low power, to ascertain if the colour reaction has suc- 

 ceeded. As a rule the last process requires to be repeated twice or 

 thrice. The desired effect is attained when the other tissue elements 

 are blue and the mucus cells are red-violet. The carbol-xylol is re- 

 moved by means of xylol. 



* Deutsche Med. Wochenschr., xxvii. (1901) Bedage, p. 116. 



t Oentralbl. Bakt, l t0 Abt., xxx. (1901) pp. 281-4. 



X Arch. Mikr. Anat. u. EntwickL, Iviii. (1901) pp. 67S-85. 



