MICROSCOPICAL TECHNIQUE. 297 



bacillus. For the preparation of this culture medium very fresh 

 ascitic, pleuritic, or other exudative serum is employed, to every 

 cubic centimetre of which two cubic centimetres of ten per cent, 

 caustic potash solution is added, so as to convert the serum 

 albumin into an alkaline form that remains soluble on sterilisation 

 by heat. To this is added agar (one and a-half to two per cent.) 

 that has been softened previously in acidulated water. The 

 mixture is steamed till the agar is completely dissolved. The 

 whole is then transparent, and filters readily through coarse paper 

 (in a hot funnel). Then four or five per cent, of glycerine is 

 added, and also a half to two per cent, of grape sugar, if desired. 

 Then it is poured into tubes, and allowed to solidify after 

 steam sterilising. It is well to test the serous exudation employed, 

 by boiling a little in a test tube before adding the agar. If this 

 serous fluid then coagulate, because of an unusual excess of 

 albumin, there should be added at least its bulk of distilled water, 

 and the diluted serum then treated as above indicated. — New 

 York Med. Journal. 



Staining' Actinomyces.— Marpmann contributes an article on 

 this subject to the Zutschrift Jiir Angewa?idie Mikroskopie^ from 

 which we {National Druggist) extract as follows : — The sections 

 (which should be cut from the most infected tissues) are placed 

 first in absolute alcohol, and after this into the following mixture : 



Concentrated alcoholic solution of methyl- violet ... i part. 



Water ... ... ... ... ... 2 parts. 



One per cent, solution of sodium carbonate ... 2 ,, 



Leave in the stain for ten minutes, then rinse in water, and 

 put into an alcoholic solution of fluorescein, which contains a 

 small proportion of erythrosin. Here let them remain fifteen 

 minutes, than wash them off in absolute alcohol. Clear in the 

 usual. manner with xylol and lavender oil, and mount in balsam. 

 The actinomyces will show up blue. 



New Double Stain for Bacteriological Purposes— For the 



more certain determination of the micro-organisms in pus, mucus, 

 etc., Pick and Jacobsohn (in the Berli7ier Klinische Wochenschrift) 

 describe a process which for simplicity and certainty leaves little to 

 be desired, and is as follows : — 



