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Bacteriology. — Prof. Prace presents a paper from Mr. ALEX. 
KLEIN on: “Bacteriologie Researches of Human Faeces.’ 
(1st Part). 
In the estimation of quantitative bacteriologie relations in faeces, 
attention should be paid to the very irregular and unequal distri- 
bution of the lower organisms in this substance; in a great number 
of places they are accumulated in enormous masses, in other portions 
of the same faeces they are relatively scarce. In these researches 
two expedients were used in order to neutralize this irregularity, 
namely: 
1. by examining at each time a relatively great quantity of faeces; 
this offering more probability that the various unequalities are 
proportionately represented than smaller volumes. In these researches 
10 grs. (on the average thus !/,; part of the total quantity of faeces 
deposed in 24 hours by a full-grown person) was fixed as mini- 
mum; and 
2. by making an extremely fine and equal emulsion in sterilized 
water of the faeces destined for the estimation. This emulsion was 
thus prepared: the weighed faeces were for a fairly long time rubbed 
fine in a sterilized mortar and in sterilized water (mostly 100 cM’), 
by means of a sterilized pestle; when thus the substance was properly 
mixed, a certain quantity (10 eM?) was withdrawn from the mortar 
and thoroughly shaken for some time in a flask with a great 
number of small porcelain balls, under continual addition of known 
quantities of sterilized water. 
Of such an emulsion was then determined: 
a. by the culture-method the number of germs fitted for develop- 
ment, and 
b. by the microscopic counting-method the total number of bacteria 
present; for both, plates and counting-preparations, was always used 
the same platinum loop. 
Since the first publication!) of the microscopic counting-method 
I have made some modifications in the method, which are not devoid 
of importance for its practical application. 
1) Avex. Kreis. Eine neue mikroskopische Zählungsmethode der Bacteriën. Cen tral- 
blatt fiir Bact. und Par., 1 Abth., 1900, Bd XXVII, S. 834. 
Proceedings Royal Acad. Amsterdam, Vol LV. 
