116 SUMMARY OF CURRENT RESEARCHES RELATING TO 



minute. A similar amount of water is added and allowed to stand for 

 five minutes. Wash for 1-2 minutes in running water. 



If dysenteric stools are to be stained, the dye should be allowed to 

 act for 2 minutes, while for Treponema pallidum 10 minutes may be 

 necessary. 



Gram's Staining- Method. *— F. Loeffler has tested a number of 

 methyl-violets and gentian-violets in their relation to Gram's method. 

 The best results were obtained with methyl-violet 6 B and B N in 

 10 p.c. solution freshly dissolved in 1-2 '5 p.c. aqueous carbolic. 

 Sections taken from alcohol were placed in the stain solution for 2 to 10 

 minutes, washed in water, transferred to Gram's iodine solution for 2 

 minutes, then into 5 p.c. aqueous nitric acid or sulphuric acid for 1 

 minute (or for 10 seconds into 3 p.c. alcoholic hydrochloric acid), and 

 finally into absolute alcohol until completely decolorised ; cleared in 

 xylol, and mounted in balsam. 



Studying the Nerve-endings in the Urinary Bladder of Mammals. 

 Sergius Michailowf treated the material by the supravital method. 

 Pieces of quite fresh bladder were immersed in the Ringer-Locke fluid, 

 to which methylen-blue had been added, and when sufficiently stained 

 the tissues were fixed with 7-10 p.c. molybdanate of ammonium. The 

 pieces were then washed with water, dehydrated, and mounted in balsam. 

 Occasionally the material was stained with Grenadier's alum-carmin. 



Staining-tank with Movable Grooves. % — Casimir Cepede describes 

 a staining-tank with movable grooves. These slots or grooves are like 

 the tanks made of glass or porcelain, and are of such dimensions that 

 the pieces can be easily removed. This device enables the various parts 

 of the tank to be easily cleaned. 



Simple Method of Staining Blood-films.§ — F. Weidenreich places 

 in a watch-glass or capsule some 5 c.cm. of 1 p.c. osmic acid solution, and 

 adds 10 drops of acetic acid. Perfectly clear slides are laid over the 

 glass pan and exposed to the action of the paper for 2 minutes ; the 

 capsules should be covered during the exposure with a bell-jar. The 

 blood obtained in the usual way is then made into a film on the side of 

 the slide which has been exposed to the paper. The slide is at once 

 returned to the bell-jar for about 1 minute. When the film is quite dry 

 the slide is passed thrice through the flame and then is flooded for 

 about a minute with a very dilute solution of potassium permanganate 

 (pale red hue). The film is then washed with water and mopped up 

 with filter paper, after w r hich it is ready for staining, for which purpose 

 the following are suitable : Ehrbch's tri-acid mixture, Giemsa, gentian- 

 violet, eosin-methylen-blue, haematein. 



* Centralbl. Bakt., lte Abt. Ref.. xi. (1907) p. 78. 

 t Arch. Mikr. Anat., lxxi. (1907) pp. 254-83 (2 pis.). 

 % C R. Soc. Biol. Paris, lxiii. (1907) pp. 485-7 (2 figs.). 



§ Folia hamatologica, iii. (190G) 7 pp. See also Zeitschr. Wiss. Mikrosk., xxiv. 

 (1907) pp. 301-2. 



