118 SUMMARY OF CURRENT RESEARCHES RELATING TO 



saline with 1 per 1000 neutral red. Ten drops of each solution are 

 mixed in a tube, and then 1 drop of Mood, or 1-4 drops of the sediment 

 of a centrifuged exudate. The tube is incubated at 37° for 2<> minutes, 

 and then the liquid is examined in a glass cell and the living and dead 

 leucocytes separately enumerated. 



New Method of Demonstrating Spirochteta pallida.* — J. T. 

 Lenartowicz and K. Potrzobowski give the following procedure : Per- 

 fectly clean slides are exposed to the vapour of 1,-2 p.c. osmic acid for 

 5 seconds ; the vaporized side is then covered with a smear of the 

 material to be examined ; the smear is at once fixed for 10 to 20 seconds 

 with osmic acid vapour, and when quite dry.is stained for \ to 1 minute 

 with the Ziehl-Neelsen carbol-fuchsin tubercle stain. This done, the 

 preparation is washed with water, dried and examined under an oil- 

 immersion. It is important to notice that the exposure to the osmic 

 acid vapour should not exceed the time given above. In successful 

 preparations the ground is stained red, and upon this Spirochseta pallida 

 stands out as an unstained appearance ; other bodies, such as S. refringens, 

 red corpuscles and bacteria, stain well ; hence, according to the authors, 

 this procedure not only facilitates the search for 8. pallida, but also 

 serves for a differential diagnosis. The method is also useful for 

 detecting flagella. 



Use of Picramic Acid for Staining.f — A. Frohlich, after alluding 

 to the ill qualities of picric acid, recommends as substitute picramic acid, 

 and gives the following procedure : (1) Stain in hsemalum, wash in tap 

 water, or in faintly ammoniacal distilled water until blue. Transfer to 

 saturated alcoholic solution of picramic acid for 3 to 5 minutes or longer. 

 Wash quickly in absolute alcohol. Next immerse in saturated alcoholic 

 solution of chromotrop 2 R or 6 B (Hochst) for | to 2 minutes until the 

 sections begin to turn red. Lastly, a short wash in absolute alcohol, 

 xylol -alcohol, xylol-balsam. 



Combined Staining Methods for Tubercle bacilli.^ — S. Hatano 

 gives two methods for the better staining of tubercle bacilli : (1) Stain 

 with warm carbol-fuchsin for 5 minutes ; wash ; 25 p.c. sulphuric acid 

 for 10 to 30 seconds : 75 p.c. alcohol until all the colour has disappeared. 

 Stain with methylen-blue solution for 2 minutes and wash. Then 

 Gram's stain. In the second method the procedure is reversed. 



Staining in bulk with Hematoxylin^ — ('. Morel and Bassal fix 

 in a mixture the following solutions: A. Bichromate of potassium 2, 

 water 100. B. Formol 10, acetic acid 10, water .So. for 8 to 20 hours. 

 The pieces are thoroughly washed in running water for 24 hours, and 

 then immersed for 1 day in 95 p.c. alcohol. The pieces are then placed in 

 a freshly made mixture of the two following solutions : I. Hematoxylin 

 1 grm., 1)5 p.c. alcohol lOOc.cm. II. Perchloride of iron 2 c.cm. ; hydro- 



* Centralbl. Bakt., lvi. (1910) pp. 18G-91 (1 fig.), 

 t Zeitscbr. wiss. Mikrosk., xxvii. (1910) pp. 549-52. 



% Berlin Klin. Wocbenscbr., xlvi. (1909) pp. 1694-5, through Zeitscbr. wiss. 

 Mikrosk., xxvii. (1910) p. 313. 



§ Journ. Anat. et Physiol., xlv. (1909) pp. 632-3. 



