ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
141 
therefore, various experiments, and found the following method satis- 
factory. The fresh ovaries were teased apart in very dilute osmic acid, 
washed in distilled water, and placed in a 1 per cent, solution of silver 
nitrate, where they remained for half an hour ; they were then put into 
acetic acid for the same length of time, and placed in the sunlight. On 
examination under the Microscope the cell-boundaries were distinctly seen. 
Simple Method of examining living Infusoria.* — Herr J. Eismond 
has discovered a method of slowing those rapid movements of Infusoria 
which make the examination of these objects during life so difficult. 
The method is based on that of crystallographers, who retard the forma- 
tion of crystals by the addition of a colloidal material. He added a 
drop of thick watery solution of cherry-gum, and obtained the desired 
effect. In a very short time the Ciliata were seen to be imprisoned, 
with all their cilia moving actively, but effecting no change in position. 
All the vital processes can be most satisfactorily observed in Infusoria 
so treated, and a certain amount of locomotion can be allowed by using 
a less dense solution. Small Crustacea, Worms and Flagellata, and 
other marine animals, may be well studied by this method. It may be 
added that gum-arabic and other fixing materials are useless. 
New Method for demonstrating Tubercle Bacilli in Sputum.f — 
Dr. E. Czaplewski recommends the following method which he says 
gives ideal pictures in about three minutes of tubercle bacilli in sputum. 
Three solutions are required : — (1) The Ziehl-Neelsen carbolic-fuchsin. 
(2) Saturated alcoholic solution of yellow fluorescin to which methylen- 
blue is added to excess. (3) Saturated alcoholic solution of methylen- 
blue. 
A very thin layer of sputum must be fixed on the cover-glass in the 
usual manner. On the cover-glass held in a pair of forceps, sputum side 
upwards, is then let drop sufficient of the fuchsin solution to form a 
complete layer. It is then held over the flame of a spirit-lamp until it 
vaporizes or begins to boil. The fuchsin is then run off and the cover- 
glass waved to and fro in the fluorescin solution six to ten times, and 
aiter this in the methylen-blue solution ten to twelve times. The cover- 
glass is next quickly washed in pure water and then at once laid with 
the prepared surface upon a clean slide. The superfluous water is then 
expressed by means ot a piece of blotting-paper placed on the top, and 
any deposit of pigment removed with a moist cloth. Finally, a drop 
of cedar oil is laid on the back. The preparation is then ready 
for examination. Hence it will be seen that the organisms are observed 
in water, but the preparation may of course be mounted in the usual 
manner. 
Method for Differential Diagnosis of Bacilli of Typhoid (Eberth)4 — 
The procedure consists in a modification by J. Gasser of Noeggerath’s 
method for recognizing the typhoid bacillus. To a test-tube full 
of nutrient agar twenty drops of a saturated aqueous solution of 
fuchsin are added, the mixture sterilized and poured into a Petri’s 
* Zool. Anzeig., xiii. (1890) pp. 723-4. 
t Centralbl. f. Bacteriol. u. Parasitenk., viii. (1890) pp. 685-94. 
X La Semaine Med., 1890, No. 31. Cf. Bakteriol. u. Parasitenk., viii. (1890) 
p. 411. 
