254 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
The top is sloping and the sliding panels are cut out so as to allow the 
Microscope to project, and are accurately fitted to the instrument by 
means of felt. In front are a square glass window, the thermometer, 
and regulator; on the left is the opening for inserting slides. The 
Fro. 55. 
doors are behind. To the right side may be fitted the arrangement for 
moving the slide to and fro and up and down, but this is rarely neces- 
sary, and much increases the price. 
Filtering Fluid containing Bacteria.* — Prof. O. Bujwid says that 
now he only uses Chamberland’s porcelain filter, having given up the 
Berkefeld on account of its brittleness, slowness, &c. For filtering toxins 
the author works the filter from without inwards, and thus obtains a 
closed sterilised space for receiving the filtrate. Though a new bougie 
filters very quickly for 1/2-1 hour, its pores soon get blocked, and in 
order to avoid this the bougie should be removed, and its surface wiped 
with a rag moistened with distilled water. While this is being done the 
rubber tube should be tightly clamped. This purification should be 
performed every one or two hours. Filtration over, the pores of the 
* Centralbl. f. Bakteriol. u. Parasitenk., l t0 Abt., xviii. (1895) pp. 332-3. 
