ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
343 
fluid. (2) The fluid is a modified Uschinsky’s medium : — distilled water 
1000 grm. ; ammonium lactate 5 grm. ; sodium asparaginate 2*5 grm. ; 
sodium sulphate 2*5 grm.; sodium chloride 2*5 grm. ; potassium phos- 
phate (K 2 HP0 4 ) 2*5 grm.; calcium chloride 0*1 grm.; magnesium 
sulphate 0 * 1 grm. 
Instead of this fluid, Uschinsky’s medium without the glycerin 
may be used, and instead of potato-starch, rice or any other kind of 
starch. 
After thoroughly stirring up the starch in the fluid, the tubes are 
placed in a dry oven, where they are heated on 5 or 6 consecutive days 
for 2-3 hours at a temperature ranging from 75° to 85°. After the second 
heating it is advisable to put 2 ccm. of distilled water in each tube, 
to replace that lost by evaporation. 
This medium keeps well, and is adapted for fungi and bacteria. It 
is especially suited for studying the diastatic action of bacteria. 
To this starch-jelly, assimilable kinds of sugar may be added, and 
may be used for testing the nutrient value of various sugars, gums, 
or alcohol. Such substances must be added and dissolved before the 
starch. The author uses 500 mgrm. to each 10 cm. of fluid. 
New Method for Cultivating Diphtheria Bacilli.* — Dr. A. Joos 
recommends his serum-agar as an infallible medium for the cultivation 
of diphtheria bacilli. It is prepared by mixing 800 ccm. of blood- 
serum with 50 ccm. of normal soda solution, and 150 ccm. of distilled 
water or bouillon. The mixture is placed in a flat-bottomed flask, and 
then heated for 2-3 hours in a water-bath at a temperature of 60°-70°. 
The temperature is then raised to 100°, or what is still better, the flask 
is placed for one-half to three-quarters of an hour in a steam steriliser. 
An equal quantity (500 ccm.) of peptonised bouillon and 20 grm. agar 
are now added. The solution is filtered while hot, sterilised for a 
quarter of an hour in an autoclave at 100°— 110°, and then distributed 
into Petri’s capsules. In making the foregoing, the only precaution 
necessary is not to raise the temperature too quickly, lest the albumen 
of the serum be coagulated. 
The chief advantages claimed for this medium are that diphtheria 
bacilli invariably develop on it; streptococci never, and staphylococci 
scarcely at all. A diagnosis may be arrived at frequently in 5-6 hours, 
and always under 15 hours’ incubation. 
Cultivation of leprosy Bacilius/f — Herr C. H. H. Spronck ob- 
tained from the tissues and bone-marrow of two cases of leprosy cultures 
on neutralised glycerin potato, which became visible after 10 days. 
The cultures contained rodlets which were longer and thicker than 
leprosy bacilli, and were more easily decolorised after staining in the 
usual way. The bacillus was also cultivated on Loeffler’s serum and 
agar at 37°,' but there was no growth at room temperature. Transfers 
from potato cultures were always unsuccessful. 
Positive results were obtained with the serum reaction, the strength 
of which varied from 1 in 60 to 1 in 1000. 
* Centralbl. Bakt. u. Par., l ta Abt., xxv. (1899) pp. 296-304, 351-7 (10 figs.).' 
t Weekblad v. h. Nederlandsch. Tijdschrift v. Geneeskunde, Deel ii. (1898> 
No. 14. See Centralbl. Bakt. u. Par., l te Abt., xxv. (1899) pp. 257-8. 
