150 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(6) The preparations are next immersed for 5 minutes in absolute 

 alcohol which has been rendered yellowish by means of a few crystals 

 of picric acid. 



(7) The preparations are then cleared up in oil of cloves and mounted 

 in xylol balsam. 



By this procedure a triple staining is obtained. 



Staining Actinomyces.* — Dr. A. Baranski recommends picrocarmine 

 for staining Actinomyces. A small quantity of the yellow granules or 

 of the pus is spread out on a cover-glass, and having been dried in the 

 air is drawn several times through the flame of a spirit-lamp. The 

 cover-glass is then placed in the picrocarmine solution for 2 or 3 

 minutes, then washed in water or spirit and examined in water or 

 glycerin. If for a permanent specimen the cover-glass is dried after 

 having been washed and then mounted in balsam. Sections require to 

 stay in the picrocarmine solution 2-3 minutes or longer. In other 

 respects the manipulation is the same. The Actinomyces are stained in 

 various shades of yellow, the surrounding tissue being dyed red. 



Method for Disting-uishing and Isolating Cholera Bacteria. f — 

 Cholera bacilli, says Dr. 0. Bujwid, form a scum on the surface of 

 nutrient media, and this scum consists of a pure cultivation of cholera 

 bacilli. This skin or scum when grown for 2i hours at 37° C. in an 

 alkaline solution containing 1-2 per cent, peptone and • 5 per cent, of 

 salt resembles very much that formed by Bacillus suhtilis. Now cholera 

 bacilli give with certain mineral and organic acids, but specially with 

 hydrochloric, a reaction which has been shown to be due to the forma- 

 tion of indol, and of a trace of nitrite. Impure cultivations and also 

 bacteria resembling cholera bacilli also give this reaction, but it is 

 much less intense, and only takes place after a longer time. For 

 example, impure cultivations of cholera in a slightly alkaline 2 per cent, 

 peptone solution, and kept for 24 hours at a temperature of 37° C, do 

 not give any noticeable reaction, while pure cholera bacteria bred under 

 similar conditions give a beautiful purple-red colour with hydrochloric 

 acid. Hence it is possible to ascertain merely by the aid of hydrochloric 

 acid if we are dealing with pure or impure cultivations of cholera spirilla. 



It is of importance for the success of this reaction that the peptone 

 should be very good and that the time and temperature limits should be 

 carefully observed, because if cultivated at ordinary temperatures and 

 for longer periods (3 or 4 days) the same result will be obtained with 

 the acid from other bacilli, for example, Finkler's and Miller's. Hence 

 the reaction is not only qualitative but quantitative. 



Shellac Injection for the Vessels of the Eye.J — Dr. Bellarminow 

 has used shellac injection for the vessels of the eye with good results. 

 Yellow shellac is used in a thick spirituous solution. About 1 part 

 of shellac to 1^ parts alcohol are placed in a flask for 24 hours and fre- 

 quently shaken. The mixture is then heated at 45°-50° for 2-5 hours, 

 and then filtered through two or three thicknesses of gauze. The 

 syrupy filtrate is then stained with cinnabar or Berlin blue, and used 

 for injecting arteries or veins. It will not penetrate the capillaries, 

 and if required for this purpose should not be thicker than cream. 



* Deutsch. Med. Wocheuschr., 1887, p. 1065. 



t Central bl. f. Bakteriol. u. Parasitenk., iv. (1888) pp. 494-6. 



X Anat. Anzeig., iii. (1888) pp. 618-50. 



