500 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Stained for 16 hours, and differentiated with iron-alum for 20 seconds 

 only. The correct degree of differentiation was gauged by examining 

 under an oil-immersion. 



New Method of Staining the Tubercle bacillus.* — ^M. Barlaerio's 

 method consists in staining the film with a solution of magenta and 

 phenol, and afterwards treating it with a dilute solution of nitrous acid, 

 which does not affect the staining of the tubercle l)acillus, but decolorises 

 most bacteria owing to the conversion of the basic magenta i^ito a 

 ■colourless diazo-compound. The preparation is first treated for 25-30 

 minutes at 40-50° with a mixture of 2 c.cm. of a cold saturated solution 

 of magenta in 96 p.c. alcohol, and 2 c.cm. of a 5 p.c. aqueous solution 

 of phenol. It is then rapidly Avashed in water and immersed for 10-15 

 minutes in 10 c.cm. of a dilute solution of sodium nitrite (1 : 20,000) 

 containing a drop of dilute hydrochloric acid (D 1 • 12). Bacteria, other 

 than tubercle bacilli, can be stained differentially by means of methylen- 

 blue. The preparation is finally washed in water, dried, and mounted 

 in balsam. 



Tetrachrome Staining Mixture. f — G. Delamare has devised a four- 

 colour solution for simultaneously staining nuclei and connective, 

 elastic and muscular tissue. It consists of two solutions which are 

 mixed in equal parts. The first is composed of orcein, 1 grm. ; 

 hydrochloric acid 1 c.cm., absolute alcohol 50 c.cm. ; the second of 

 Ehrlich's lijematoxylin 2 c.cm., saturated aqueous solution of acid 

 f uchsin 1 c.cm., saturated aqueous solution of picric acid 200 c.cm. The 

 paraffin sections are first immersed in slightly acidulated water, and 

 afterwards in the stain at 45° for 20-30 minutes. On removal they are 

 rapidly washed in acidulated water (4 or 5 drops to 100 c.cm.), and then 

 placed in tap water to bring out the blue of the hajmatoxylin. Then 

 alcohol, xylol, balsam. Nuclei, blue ; muscle fibre and protoplasm, 

 yellow ; connective- tissue, yellow ; elastic fibres, black. 



Examining the Sputum in Cancer.l—L. Follet has found a micro- 

 organism with double contour, and apparently a yeast in the sputum of 

 persons affected by cancer. He stains fresh unfixed films with the 

 following mixture : glycerin, 40 ; methylen-blue, 2 ; carbolic acid, 0*5. 

 The ingredients are dissolved and the mixture filtered. In order to 

 obtain permanent preparations he adopts the following procedure : 

 40 grm. chloroform, 20 grm. liquid ammonia, and 10 grm. of carbolic 

 acid are mixed in a flask, and after a few hours the chloroform is 

 syphoned off, and then to this carbolate of ammonia a gramme of 

 methylen-blue is added ; the mixture is then filtered. A film of the 

 sputum to be examined is made in the usual way, and stained without 

 heating ; a few drops of chloroform are poured on the film, and when 

 this has evaporated, the slide is washed in running water and afterwards 

 dried with blotting-paper. The films may also be stained with the 



* Rend. Accad. Sci. Fis. Mat. Napoli, xii. (1906) pp. 446-9. See also Journ. 

 Chem. Soc, xcxi.-xcxii. (1907) p. 381. 



t C.R. Soc. Biol. Paris, Iviii. (1905) pp. 828-9. 

 X Tom. cit., Ixii. (1907) pp. 790-2. 



