ZOOLOGY AND BOTANY, .MICKObCOPY, ETC. 751 



Method for Accelerating Slow Staining by Electric Current.* — . 



Foix aud Malleiu, using a Leclaiiche battery giving 4 volts, have found 

 that, by passing the current through the staining solution during the 

 process of staining, it is possible in 10 rainates to stain S^nrochceta jmllida 

 a violet colour with Giemsa's fluid ; the red blood cells lieing stained, 

 not pink as usual with this stain, but green or pale blue. Similar 

 acceleration was obtained with staining tubercle bacilli by Ziehl's 

 method ; the bacilli being thoroughly stained after 10 minutes. 



Staining Negri's Corpuscles.! — 0. Lentz takes from the cornu 

 ammonis pieces 2-3 mm. thick and places them in aceton for 1 hour at 

 87° ; the pieces are next saturated with paraffin m.p. 55° for 1^ hour 

 at 58° aud then imbedded. The sections, stuck on by the water 

 method, are freed from paraffin with xylol and then stained. The 

 solutions required are: — (1) eosin extra B 0*5, 60 p.c. ethyl-alcohol 

 100 ; (2) Loeffler's methylen-blue ; (3) absolute alcohol 30, 1 p.c. 

 solution of caustic soda in absolute alcohol 5 drops ; (4) absolute 

 alcohol 30, 50 p.c. acetic acid 1 drop ; (5) Gram's iodine solution. 



Two procedures are given : — A. (1) Stain in the eosin solution 

 1 min ; (2) wash in water ; (3) stain in methylen-blue solution 1 min. ; 

 (4) wash in water ; (5) mop up on blotting-paper ; (6) differentiate in 

 alkalin-alcohol ; (7) differentiate in acid-alcohol ; (8) wash in absolute 

 alcohol ; (D) xylol-balsam. Films and smears need only be dried 

 after (8). 



B. (1) Stain in eosin solution for 1 min. ; (2) wash in water ; (3) 

 stain in methylen-blue solution 1 min. : (4) wash in water ; (5) mordant 

 with the Lugol solution ; (6) wash in water ; (7) differentiate in methyl- 

 alcohol ; (8) wash in water ; (9) contrast stain in methylen-blue solu- 

 tion for I min. ; (10) then proceed as in A from (4) onwards. 



Procedure B gives the more definite picture, but in both the bodies 

 are red bestippled with blue spots. 



New Method of Flagella Staining4— H. C. Plant describes the 

 following method, which is a combination of the Ermengem and Zettnow 

 procedures. (1) The material consists of a loopful of culture in ^ c.cm. 

 of 2 p.c. formalin solution, (2) The slides to be used are treated with 

 hot strong sulphuric acid, followed by washing, 15 p.c. caustic soda, 

 washing, alcohol, rubbing with fine linen cloth moistened with alcohol- 

 ether mixture aa. (3) Upon the cleaned slide is placed a drop of boiled, 

 filtered, distilled water, and with this is mixed a loopful of the formalin- 

 bacteria mixture. (4) After drying under cover, the film is fixed for 

 1 hour in a mixture of equal parts of alcohol and ether. (5) It is then 

 mordanted with iodopotassic-iodide solution (1-2 : 300) for 3 minutes ; 

 this is followed by alcohol and then water. (6) The film is further 

 mordanted ])y Ermengem's method : 2 p.c. osmic acid 1 part, 10 p.c. 

 tannin 2 parts (to 100 c.cm. 5 drops acetic acid). The film is left 

 covered with the foregoing solution for 4 hours at room temperature, or 

 for half an hour at 50° ; it is then washed with water and alcohol 



* C.R. Soc. Biol. Paris, Ixii. (1907) p. 1201. 



t Centralbl. Bakt., It^ Abt. Orig., xliv. (1907) p. 374-8 (3 photos and 2 pis.). 



X Tom. cit., pp. 310-16 (1 pi.). 



