ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 297 



but in the " number of bacteria per cubic centimetre." The gauging 

 is done in the same way, except that the dry weights will be replaced 

 by microscopical numberings. It must be noted, however, that owing 

 to the optical properties of the emulsions, the numbers obtained in this 

 case correspond only to fictitious bacteria with a known mean weight or 

 volume, a balance being made — in constant quantities of substance — 

 between the number and size of the elements when these are not iden- 

 tical with those of the type emulsion. 



Under the heading of " Opacity Constants " the authors suggest that 

 the measurements may be verified from time to time by the use of opal 

 glasses in sheets of varying thickness. J. E. 



B. Technique. 

 (i) Staining and Injecting-. 



Note on the New Rapid Staining of Blood and Parasites in 

 Films.— Roger Arnaud (C.B. Soc. Biol, 1919,82, 208-9). Prepare 

 film in the ordinary manner ; do not fix. Place film face downwards 

 in a Laveran-Mesnil box ; cover freely with May-Grunwald stain. 

 Cover box to prevent evaporation of the methyl-alcohol. Leave film to 

 stain for 5 minutes, then remove excess of stain, and without washing 

 cover film with a solution of borated blue (Manson), prepared as follows : 

 Put a few drops of the concentrated solution in tube. Add distilled 

 water until the fluid is almost translucent. Use this solution to cover 

 the film. Allow stain to act 40 to 50 seconds. "Wash in distilled water. 

 Differentiate in 90 p.c. alcohol. Wash again, dry and examine. Red 

 blood cells are stained violet-black, eosinophile granules deep red ; 

 neutrophile granules are clearly visible, as are also the basophile 

 granules. Parasites show light blue protoplasm and deep red nuclei. 

 (Hanson's borated-blue is prepared by dissolving 2 grms. of methylen- 

 blue in 100 c.cm. of 5 p.c. solution of borax, prepared with boiling 

 water.) J. E. 



(6} Miscellaneous. 



Antiseptic Treatment ofWounds. — Hiroshi Tsuji and Kakugoro 

 Taghibana {Actx Scholse MedicinaUs, Kioto, 1918, 11, 387-97). Work- 

 ing on similar lines to Watson Cheyne, the authors have investigated 

 the action of diffusive germicides upon Staphylococcus aureus, Strepto- 

 coccus longus, Bacillus pyocyaneus, and B. coli, through a stratum of 

 2 p.c. agar, employing a modification of Edmund's cell. Among the 

 antiseptics examined, cyanocuprol, potassium iodide, tincture of iodine, 

 hydrogen peroxide, carbolic, creosote, and the organic pigments showed 

 a higher diffusibility. All except potassium iodide, hydrogen peroxide, 

 and brilliant green cause a more or less marked precipitation of the 

 albumin in agar. The diffusibility of sublimate was not so weak as, 

 hitherto, generally considered ; it diffused in a short time deeper into 

 agar than did alcohol. The iodine in iodo-potassium iodide solution or 

 tincture of iodine precipitated the albumin, whilst the solvents them- 

 selves (the iodide of potassium solution and alcohol) affected the agar 



