386 SUMMARY OF CURRENT RESEARCHES RELATING TO 



He found, also, that the fine Berkefeld W filter stopped all bacteria, 

 when subject to a pressure of not more than two atmospheres. 



The author emphasizes the importance of washing, scrubbing, and 

 boiling the filter after use in order to prevent subsequent clogging. 



Indian-ink Method of Demonstrating Spirochseta pallida.*— - 

 Friihwald used the following technique : the surface of the lesion is 

 scraped until a drop of serum is obtained ; a loopful of this is mixed on 

 a sbde with a drop of commercial Indian ink (Giinther and Wagner's). 

 The mixture is then spread with the edge of a coverslip, after the manner 

 of a blood-film. When dry the smear is examined with an oil-immersion. 

 The spirochetes are seen as bright spirals on a dark brown field, and 

 pallida can be distinguished from other spirochetes by its form. By 

 this method the author claims that Spirochseta pallida can be demon- 

 strated more quickly than by any other procedure. 



New Drop Bottle. — F. R. Chopping showed at the Meeting held on 

 April 20 a drop bottle which has been designed to hold staining reagents. 



Fig. 51. 



It is a modification of " Schuster's Alkalimeter " ; the glass stopper is 

 replaced by an indiarubber teat ; manipulation of this produces any- 

 thing from a fine steady stream for washing over slides to a single drop 

 for staining purposes. The bottle holds rather more than the alkali- 

 meter, and has been made in squat form with a wide base, giving it 

 great stability, which experience has shown to be very desirable. A 

 special advantage is that it can be used with equal facility with either 

 hand (fig. ">1). 



The appearance is neat and the price moderate : the bottles shown 

 were made by Messrs. Baird and Tatlock (see post, p. 397). 



* Munch. Med. Wochenschr., No. 49 (1909). 



