236 SUMMARY OF CURRENT RESEARCHES RELATING TO 



a solution consisting of 3 p.c. potassium bichromate and sulphuric acid 

 (100 : 5), and after having been washed in water are kept in alcohol. 

 When required for use they are picked up with horn-tipped forceps and 

 flamed. The material used should be obtained from fresh cultures. The 

 best are those which are solid, contain little salt, and are prepared with 

 glycerin. A loopful of culture is placed on a watch-glass containing 

 5 c.cm. of distilled water, and a drop of the suspension spread over the 

 cleaned cover-glass. The cover-glass is then placed under a bell-jar and 

 allowed to dry slowly with the aid of calcium chloride. For staining,, 

 two solutions are required : (a) potassium permanganate 25 eg., distilled 

 water 10 grm. (b) To a calcium chloride solution (0*75 grm. in dis- 

 tilled water 100 grm.) in the proportion of 20 to 1 is added a 1 p.c. 

 solution of neutral red. The cover-glass is then laid in the potassium 

 permanganate solution for 10 to 20 minutes, and after having been 

 washed in distilled water is transferred to the neutral red solution for 

 15, 20, or 30 minutes, according to the kind of bacterium dealt with. 

 The cover-glasses are then washed, dried with blotting-paper, and mounted 

 in balsam. 



Staining the Reticular supporting Network of Malignant Neo- 

 plasms by Mallory's Method.* — P. G. Woolley recommended that sec- 

 tions should be cut from tissue hardened in Zenker's fluid and imbedded 

 in paraffin. These are fixed to the slide in the usual way, and then the 

 paraffin is dissolved off and the slide immersed in absolute alcohol, 95 p.c. 

 alcohol, 70 p.c. alcohol, then in water. Next, the sections are stained in 

 a -j 1 ^ p.c. aqueous acid fuchsin solution for 2-3 minutes and then washed 

 in water. After this, the sections are treated for 5-7 minutes with a few 

 drops of 1 p.c. solution of phospho-molybdic acid. After again washing 

 in water the sections are stained with a solution composed of anilin-blue 

 0*5 grm., orange Gr 0*2 grm., oxalic acid 2 grm., water 100 c.cm. 

 This is allowed to act for about 20 minutes, after which the slides are 

 rinsed in water and then hurriedly dehydrated with 95 p.c. alcohol. 

 Finally, the sections are treated with a drop or two of anilin oil which 

 is allowed to remain on until the sections are clear. It is then removed 

 with blotting-paper, and the sections having been treated with xylol are 

 mounted in balsam. By this method the finest reticular processes can 

 be seen clearly and distinctly. 



Staining Reactions of Proteid Crystals.! — J. A. Milroy finds that 

 albumin crystals, prepared by the method of Hopkins and Pinkus, after 

 treatment with trichloracetic acid have a selective affinity for acid as 

 distinguished from basic anilin dyes. If, however, they are further 

 treated with alcohol they become capable of taking up either acid or 

 basic dyes. In the latter case the staining is to be regarded as a physical 

 phenomenon, while in the former it is largely chemical. 



Improved Method for the Microscopical Diagnosis of Inter- 

 mittent Fever.} — Ronald Ross recommends the following method by 

 which a thick film of blood is treated in a manner which does away with 



* Johns Hopldns Hosp. Bull., xiv. (1903) pp. 21-4 (3 figs.). 

 t Proc. Soot. Micr. Soc, iii. (1901-1902) pp. 252-7. 

 J Lancet, 1933, i. p. 86. 



