ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 115 



aqueous solution of tropseolin 00 5 parts, acetic acid 0*5, water 100. 

 They are then washed with water. In order to decolorise the prepara- 

 tions more slowly, the tropasolin solution may be diluted 5-10 times with 

 water. 



Giemsa-staining of Spirochseta pallida.* — J. Schereschewsky ex- 

 poses the prepared slide, the film being still moist, to osmic acid vapour 

 for a few seconds, and after drying in the air fixes in the flame and 

 then treats it with Giemsa's stain in the following way : 13 drops of 

 Giemsa solution are diluted with 10 com. of 0*5 p.c. glycerin and heated 

 to boiling, and if no precipitate occurs the film is treated therewith. 

 Aiter 2 or 3 minutes the solution is poured off, and if the preparation 

 be not sufficiently stained, the operation is repeated. After a short wash 

 the preparation is mopped up with blotting-paper, dried, and examined 

 in the usual way. 



Staining Sudanophil Leucocytes.f — D. Bultino and Gr. Quarelli used 

 the following solutions for staining the fat globules in leucocytes : 

 • 2 p.c. solution of Sudan iii in absolute alcohol, and aO'l p.c. solution 

 of brilliant Kresyl-blue in the same medium. The authors found that 

 the percentage of sudanophils is much increased in all suppurating 

 affections and in pneumonia. 



Borrel's Blue.! — E. Pinoy states that Borrel's blue is conveniently 

 made by mixing 100 grm. distilled water, 1 grm. silver oxide, and 1 grm. 

 medicinal methylen-blue. The mixture should be kept in a yellow 

 glass bottle. After three weeks, during which period the flask should 

 be shaken from time to time, it is filtered. The maturation may be 

 hastened by keeping the fluid at 37° C. Its staining property depends 

 much on the quality of the methylen-blue. 



New Method of Preparing the Romanowsky Stain.§ — N. MacL. 

 Harris gives the following procedure. Make up a saturated solution of 

 Griibler's aqueous yellow eosin in methyl-alcohol and preserve ; then 

 mix 2 grm. medicinal methylen-blue and 9 grm. sodium bicarbonate, 

 and triturate in mortar. Remove to beaker of 250 c.cm. capacity and mix 

 in 25-30 c.cm. distilled water ; steam sterilise for an hour and a quarter. 

 Grind up the black residue, mix with 200-250 c.cm. water and add 10 c.cm. 

 of 4 p.c. sodium hydrate. Extract with chloroform and then evaporate 

 off the chloroform in a water-bath. The resulting mass is made up 

 largely of methylen-violet, variable amounts of methylen-azure, and 

 other substances. Dissolve the mass in methyl-alcohol ; this makes the 

 stock solution of crude methylen-violet and azure. 



To make the staining fluid, take of the stock solution 60 c.cm.. of 

 methyl-alcohol 33 c.cm., of the stock eosin solution 1-1 • 5 c.cm. Bottle 

 and add from 0* 05-0 '15 grm. methvlen-blue. 



The staining of blood-films is carried out by Wright's method, the 

 film being covered with the solution, which is allowed to act for one 



* Centralbl. Bakt., lte Abt. Orig., xlv. (1907) pp. 91-4 (1 pi.). 

 t Rev. Clin. Med. Florence, 1907, pp. 321 and 337. See also Brit. Med. Journ., 

 1907, ii., epit. 108. J Ann. Inst. Pasteur, xxi. (1907) pp. 633-4. 



§ Johns Hopkins Hosp., Bull, xviii. (1907) p. 281. 



I 2 



