ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 2 1 5 



sion. A delicate film containing Protozoa will appear on the surface of 

 the liquid, and this can be removed by floating cover-slips over it and 

 stained by the usual methods. 



(4) Staining- and Injecting-. 



McFadyean Staining Reaction for Anthrax Bacilli.* — J. D. E. 

 Holmes reports that he has used the violet reaction in the diagnosis of 

 anthrax for some years, and has never failed to obtain a positive result 

 in anthrax blood. It is important that the original directions should be 

 strictly followed. The film should not be too thin and should not be 

 completely fixed : the temperature should not much exceed 100° C. if 

 heat be used. Fixation may also be effected by immersing the dried 

 films in absolute alcohol or methylated spirit for a few minutes. The 

 preparation must not be washed in alcohol after staining. The staining 

 solution should be freshly prepared from pure medicinal methyleu-blue. 

 Performed according to the original rite, the body of the bacillus is 

 stained violet, and is surrounded by a well-marked pink capsule. 



Staining Connective-tissues.f — P. Kriiger recommends the follow- 

 ing procedure. His method succeeds best after fixation in sublimate- 

 acetic acid (5 p.c. solution and 5 p.c. acid). The sections (frozen, 

 paraffin, or celloidin) are placed in iodopotassic-iodide solution until 

 they are dark yellow. The preparation, having been rapidly washed, is 

 placed in a solution of hematoxylin composed of : (1) a saturated solution 

 of crystalline hematoxylin dissolved in absolute alcohol ; (2) saturated 

 solution of ammonia alum ; (3) pure glycerin ; and (4) methyl-alcohol. 

 The constituents are mixed in the following proportions : (1) 100 c.cm. ; 

 (2) 3750 c.cm.; (3) G25 c.cm.; and (4) 625 c.cm. This must be 

 allowed to mature for at least three months. In this solution the 

 sections are immersed for several hours to a day or more. When 

 removed the preparations are washed in distilled water and then 

 differentiated with hydrochloric acid-alcohol. Any excess of acid should 

 be removed with ammonia-alcohol. Contrast-staining is best effected 

 with eosin. The hematoxylin solution is approximately the same as 

 Helafield's. The illustrations are very effective. 



(5) Mounting-, including- Slides, Preservative Fluids, etc. 



Mounting Preparations of Amyloid Material.! — T. Mironisco 

 gives the following method for mounting sections of material containing 

 amyloid. The sections are made on a freezing microtome, and are then 

 treated with a 1 p.c. solution of methyl-violet for 1 to 2 minutes. They 

 are then washed for 2 or 3 minutes in a 2 p.c. solution of acetic acid, 

 and afterwards with distilled water. After draining off the water one 

 or two drops of a thick clear solution of gum-arabic are placed on this 

 preparation. The slide is then placed in an incubator until the surface 

 of the gum is dry. It is then mounted in balsam. In this way ex- 

 cellent permanent preparations can be obtained. The drying of the 



* Agric. Research Inst. Pusa, Bull. No. 36 (1913) 3 pp. (1 pi.), 

 t Arch. Mikr. Anat., lxxxiv. (1914) pp. 75-90 (1 pi.). 

 % C.R. Soc. Biol. Paris, lxxvi. (1914) pp. 215-16. 



