664 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
and the stem left for a few hours. If a living stem be used, the stain 
is chiefly confined to the conducting elements, and hence a differential 
staining is afterwards obtainable. The fuchsin is replaced by weak 
picric acid ; this darkens and fixes the tissue, and when it comes 
through clear the stem is removed and transferred to 90 per cent, alcohol. 
In a few days it is decolorised and fit for sectioning. The sections 
may be contrast-stained with haematoxylin. 
If required for dissection of the vascular system, the preparation 
may be immersed in, instead of injected with, weak picric acid, and then 
preserved in alcohol. 
Romanowski’s Staining for Bacteria.* — Prof. E. Zettnow has re- 
eorded his experience of Romanowski’s eosin methylen-blue staining. 
He divides methylen-blues into two categories, those with green and 
those with violet-red reflex, and expresses his preference for the Hoch- 
ster medicinal samples. The Hochster methylen-blue is made up to 
a 1 per cent, solution, and 1 drop of 5 per cent, caustic soda solution 
is added to 1 ccm. The eosin recommended is brom-eosin B A extra 
Hochst. in 10 per cent, solution. 
The best proportion of the blue to the red solutions is as 2-1, and 
2 drops of soda solution are added after mixing 2 ccm. of methylen-blue 
solution with 1 ccm. of eosin solution. 
The cover-glasses are stained for 2-5 minutes, then washed with 
water, and examined. The preparations do not keep. 
For differentiating and decolorising were used: — ( a ) for blood pre- 
parations, acetic-acid-methylen-blue (2 grm. methylen-blue in 400 ccm. 
water + 1 ccm. acetic acid) ; ( b ) for bacteria, eosin 1-500, or methylen- 
blue 1-10,000, or solution a. 
Blood preparations were usually differentiated with one washing of 
the acetic-acid-methylen-blue. Bacteria were often treated two to six 
times with eosin solution, with a short washing afterwards with 1- 
10,000 methylen-blue. The specimens prepared by this method, as 
shown in the coloured plate, are extremely elegant. 
Modification of the Aronson-Phillips Method for Staining Mal- 
arial Blood.f — Mr. E. G. Horder recommends the following modifica- 
tion of the Aronson-Phillips method : — 
(1) Preparation of Cover. — Have ready a cover-glass in a pair of 
Ehrlich’s forceps, and in another a piece of gutta-percha 1/2 in. 
square. Prick the ear and touch the drop with the edge of the gutta- 
percha. The latter is then laid flat and drawn across the cover-glass, 
commencing from the edge held by and parallel to the forceps. In 
this way 10 or 20 different smears can be made in a few moments. 
(2) The Heating. — The cover-glass is passed 16-18 times through 
the flame of a spirit-lamp, the wick of which is 1/2 in. long. 
(3) The Staining. — The best stain is made from Ehrlich- Biondi 
powder (Griibler). The solution, as given from Cabot in a note, is made 
by dissolving 15 grm. of the ponder in absolute alcohol 1 ccm. and 
distilled water 6 ccm. The solnutio is made up as required. The time 
required for staining is two minutes or less. 
* Zeitschr. f. Hygiene u. Infektionskr., xxx. (1899) pp. 1-18 (1 pi. with 9 
•coloured figs.). t Lancet, 1899, ii. p. 889. 
