544 SUMMARY OF CURRENT RESEARCHES RELATING TO 
through paper. By deferring filtration to the next day the filtrate will 
be clearer. 
The chief feature in this method is the preliminary step of moistening 
the powdered agar and pepton with a small quantity of water or bouillon, 
and rubbing to a smooth paste free from lumps. 
Magnesia-Gypsum Plates for Cultivating Nitrifying Organisms.* * * § 
— Herr V. Omeliansky states that he has obtained excellent results from 
cultivating nitrite-forming organisms on gypsum blocks saturated with 
Winogradsky’s solution (vide infra). A perfectly uniform mixture of 
gypsum and carbonate of magnesia is prepared of the consistence of sour 
cream. This is then poured out on to a glass plate, and when it has be- 
come of a doughy consistence, is cut up into circles for Petri’s capsules, 
and into strips for test-tubes. The circles and strips, properly smoothed 
off are placed in capsules or tubes along with mineral solution, and, 
after being properly sterilised, are inoculated with nitrite-forming organ- 
isms. Growth is first visible in four or five days, the colonies being of a 
yellowish hue, ultimately becoming brownish. 
Cultivation Medium for Snirillum volutans.t — Dr. Vogt obtains 
copious development of Spirillum volutans on the following medium. 
Peas are boiled in water‘(l-5) for about 5 minutes, and the fluid strained 
through a linen cloth. To the pea-water are added 1 per cent, each 
of pepton, sodium chloride, and carbonate of ammonia. Even without 
the pepton S. volutans thrives on the medium, but sodium chloride and 
carbonate of ammonia are indispensable. The mixture must now be 
allowed to stand for some days — in fact, until it begins to decompose — 
before it is sterilised. If it be sterilised as soon as it is made, the 
spirillum does not find the medium suitable to its needs. 
Cultivating Leprosy Bacilli.J — Dr. J. Barannikow, in a preliminary 
communication, states that he has successfully cultivated typical leprosy 
bacilli from two cases. The material used was nasal secretion, sweat, 
and blood. Rapidity of growth was found to depend chiefly on suitability 
of medium. Skin, brain, and ascitic fluid were favourable starting media. 
On suitable media rodlets were found in 36-48 hours. Agar and gelatin 
containing substances suitable for the bacilli produced colonies at 17°- 
18° C. by the fourth day. If the medium was unfavourable, no growth 
took place even at body heat. 
(2) Preparing- Objects. 
Methods used for Chilopoda.§ — 0. Duboscq devotes a special chap- 
ter in his paper to technique. He usually killed his specimens with 
chloroform, cut them in fragments, and fixed with Flemming’s solution 
or Perenyi’s liquid. For the latter he used the following formula : — 
Equal parts of 1 per cent, chromic acid, 10 per cent, nitric acid, and 
95 per cent, alcohol. He also used acetic alcohol made as follows : — 
10 parts of glacial acetic acid and 100 parts of absolute alcohol ; this 
kills animals instantly in an expanded condition. For staining after 
Flemming’s solution, he recommends safranin in a saturated solution in 
* Centralbl. Bakt. u. Par.. 2 t0 Abt.. iv. (1899) pp. 652-5. 
t Op. cit., l te Abt., xxv. (1899) pp. 801-4. 
1 Op. cit., l te Abt., xxvi. (1899) pp. 113-4. 
§ Arch. Zool. Exper., vi. (1899) pp. 481-650 (7 pis. and 21 figs.). 
