698 
8UMMARY OF CURRENT RESEARCHES RELATING TO 
is joined to tlie glass tube D by a rubber tube J. D is connected with a 
pointed glass tube F, also by a rubber tube E, and the pointed end is 
inserted into a clamped tube G. The end of the tube B is somewhat 
constricted and plugged with cotton-wool ; this tube is connected by 
means of a Wolff’s bottle with an aspirator. A rubber tube joins the 
bougie to the flask H, the lower half of which is somewhat funnel-shaped. 
The neck of the flask is plugged with cotton-wool, and the vessel itself 
fixed to a stand. The whole apparatus is sterilised in an autoclave, or in 
a steamer. The autoclave not unfrequently cracks the glass vessels. 
During filtration the air is removed from the apparatus, in conse- 
quence of which the tubes G, E, J become flat, showing that the apparatus- 
is working properly and that it is air-tight. After the filtration is 
finished, the aspirator is closed and the receiver disconnected from the 
Wolff’s vessel. The clamp is removed from G to E, and the tube G 
having been removed, the filtrate can be drawn off. The object of the 
clamp M is to render aspiration with a closed aspirator possible, for if 
kept open too long damage may ensue to the apparatus ; so that after the 
air has become sufficiently rarefied the clamp M is fixed on. If the 
Wolff’s bottle be large (3 litres), the apparatus will work with the 
aspirator shut off for 12-20 hours. 
Sterilisation of Water by Ozone.* * — Dr. E. van Ermengem describes 
the system adopted at Oudshoorn for sterilising the water of the Old 
Rhine. The results appear to be very satisfactory, for not only are all 
chemical and bacterial impurities removed, but the physical characters 
are greatly improved. The system consists 
Fig. 123. in passing powerful electric currents of high 
tension through dry filtered air. The ozon- 
ised air is then forced or aspirated through 
vessels containing the water to be sterilised. 
The source of electricity is a Brush machine 
with alternating currents, and is driven by 
a small dynamo. The currents pass to two 
transformers, where they are converted into 
high-tension currents. The positive elec- 
trodes are made of thin copper or platinum 
plates, placed parallel to one another, and 
the current reaches these electrodes after 
passing through resistance-tubes 0*6 inch 
high, filled with glycerin. The negative 
pole is connected with the earth. 
Miiller-TJnkel Steam Steriliser.f— The 
chief merit of this apparatus, according to 
Dr. R. Blasius, is that it gets into effective 
working condition in about ten minutes. 
The accompanying illustration (fig. 123} 
shows the simplicity of its construction. It consists of two metal 
cylinders, the inner one being made of copper with a vaulted bottom. 
The water reservoir is circular and communicates wiili the inner cylinder 
* Ann. Inst. Pasteur, ix. (1895) pp. 673-709 (4 figs.), 
t Zeitschr. f. Angewandte Mikroskopie, i. (1895) pp. 171-3 (1° fig.). 
