566 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
required angle to the blade of the knife. The cork is raised or lowered 
by means of a finely cut screw-thread. 
The curved knife is about 5 in. in length and 1 in. in breadth, ground 
flat on the under side, and held in position by a binding-screw, after the 
fashion of several microtomes previously in use. A straight knife may 
be used if desired.” 
C4) Staining- and Injecting. 
Double-staining of Sporigenons Bacilli.* — Sig. L. Macchiati de- 
scribes the mechanical details of a process which he has found useful for 
the double staining of bacilli containing spores. The following are 
its more important points. The microbes are picked out by a 
sterilized platinum needle, and placed in a drop of sterilized distilled 
water which is evaporated in a platinum dish over an alcohol flame. 
When quite dry a staining solution is added composed of 5 grm. 
carbolic acid, 20 grm. alcohol, and 0*8 grm. fuchsin, made up to 100 grm. 
with water. When this is boiled and evaporated, the spores take up a 
rose-coloured stain which is very persistent, while the colour can be 
entirely removed from the bacillus itself by absolute alcohol. The 
bacilli can then be stained in the ordinary way by gentian- violet or 
methylen-blue. 
Carbol-methylen-blue Method.f — Herr F. Pregl advises the follow- 
ing modification of Kiihne’s methylen-blue method J as it is shorter and 
less decolorizing than the original procedure. The sections stuck on 
slide or cover-glass are stained for 1/2 to 1 minute with carbol-methylen- 
blue, with or without aid of heat. They are then washed for a short 
while with distilled water. Next they are immersed in 50 per cent, 
alcohol until they become pale blue with a somewhat greenish tinge, 
after this they are dehydrated in absolute alcohol, clearedi up in xylol, 
and imbedded in balsam. 
Spore-staining.§ — Herr Foth says that the method suggested by 
H. Moller for staining spores is excellent. The process is as follows : — 
I. Fixation by heat or absolute alcohol (2 minutes). 2. Removing fat, 
&c., in chloroform, 2 minutes. 3. 1/2-2 minutes’ action of 5 per cent, 
chromic acid. 4. Staining with phenol-fuchsin over the flame for 60 
seconds, once boiling. 5. Decolorizing in 5 per cent. H 2 S0 4 . 6. Con- 
trast staining in saturated aqueous solution of malachite-green or 
methylen-blue, 30 seconds. By this method the spores are stained red 
and the bacilli blue. 
Instead of chromic acid, chlorine water, eau de J avelle, or peroxide of 
hydrogen may be used ; indeed, for many spores chromic acid is too 
strong, and is replaced by peroxide of hydrogen with advantage. Some- 
times it is better to use anilin instead of carbolic acid with the fuchsin. 
Fixation by means of Loeffler’s device, i.e. holding the cover-glass between 
thumb and finger over the flame, is just as safe and more advantageous 
than immersing the cover-glass in chloroform, though the latter procedure 
has its advantages. 
* Malpighia, v. (1892) pp. 431-3. 
t Centralbl. f. Bakteriol. u. Parasitenk., x. (1892) pp. 826-9. 
X See this Journal, 1890, p. 254. 
§ Centralbl. f. Bakteriol. u. Parasitenk., xi. (1892) pp. 272-8. 
