450 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
solution afterwards made up to 50 ccm. After filtration, 3 drops of 
formalin are added. This solution will keep perfectly clear for 
months. 
(2) Picric acid solution is made by mixing 0*5 grm. picric acid with 
100 ccm. of distilled water. 
(3) Magnesia-water. 0*1 grm. of burnt magnesia and 100 ccm. of 
tap water are kept for a week, being frequently shaken up the while* 
and then the supernatant clear fluid poured off. 
(4) Picrate of magnesia. 200 ccm. of picric acid solution (No. 2) 
are boiled with 0 • 25 grm. of carbonate of magnesia, and, after having 
settled, filtered ; or 0 • 6 grm. of solid picrate of magnesia are dissolved 
in 100 ccm. of distilled water. 
(5) Weak magnesia-carmine. In 100 ccm. of magnesia water (Nov 
3) is dissolved O’ 2 grm. carmine by boiling for half an hour, after 
which the solution is filtered and 5 drops of formalin added. 
(6) Picro-magnesia-carmine is made by mixing 1 vol. of No. 1 with 
9 vols. of No. 4, or by adding equal quantities of No. 4 and No. 5 
together. To either solution a few drops of formalin should be added 
to every 100 ccm. 
Differential Staining of Tubercle and Smegma Bacilli.* — Accord- 
ing to Herr Honsell, the safest way to distinguish between tubercle and 
smegma bacilli is to stain with phenol-fuchsin in the usual way, wash 
and dry, and then place in acid-alcohol (absolute alcohol 97, hydrochloric 
acid 3) for 10 minutes. After this, wash in water, and stain with alcoholic 
methylen-blue diluted one-half with water. The author also notices that 
smegma bacilli of different origin behave differently as regards their 
resistance to alcohol. The method given is intended for the most re- 
sistant forms, and is far better than Grethe’s or Czaplewski’s. 
Staining of Microbes and Phagocytes.f — Dr. N. A. Iwanoff used the 
following staining method in his researches on phagocytosis. Blood 
films were made on slides or cover-glasses, and incubated for 1-1^ hours 
at 110°-120° C. The fixed preparations were then treated with the 
staining mixture for 1, 2, or 3 minutes. The staining solution was 
rendered more effective by heating the preparations over the flame for 
2-3 minutes. The staining solution was the Eoux stain for diphtheria 
bacilli two or three times diluted, and was composed of 1 per cent, 
aqueous solution of dahlia 15*0, 1 per cent, aqueous solution of 
methylen-green 45*0, formaldehyd 10 drops. To 20-25 grm. of the 
diluted Roux stain 2-4 grm. of Ziehl’s carbol-fuchsin were added. 
Staining Haematozoa of Malaria.J — Dr. E. Marchoux stained films 
of malarious blood with eosin and methylen-blue, but eventually discarded 
this procedure for a modification of Nicolle’s carbolate of thionin. The 
formula given is : — Saturated solution of thionin in 50 per cent, alcohol, 
20 ccm. ; 2 per cent, carbolic acid, 100 ccm. It is necessary to let the 
mixture mature for a few days until the phenol has combined with the 
thionin. 
* Arb. a. d. Pathol.-Anat. Inst, zu Tiibingen, ii. (1896) p. 317. See CentralbK 
Bakt. u. Par., l te Abt. xxi. (1897) p. 700. 
f Centralbl. Bakt. u. Far., l te Abt , xxii. (1897) p. 119. 
% Ann. Inst, Pasteur, xi. (1897) p. 645. 
