574 SUMMARY OF CURRENT RESEARCHES RELATING TO 



has been raised by Ehrlich with reference to his method. The pro- 

 perties which the membranous envelope of the bacteria of tuberculosis 

 seems to possess, prove that the sole disinfectants or antiseptics which 

 can be used to combat this disease, by acting on the bacteria, should 

 he alkalies and not acids, which have hitherto been employed for this 

 purpose. 



At the May meeting of the " Societe Beige de Microscopie," 

 Dr. Van Ermengem exhibited a series of preparations of tuberculous 

 bacteria obtained from expectorated matter from five patients suffering 

 from pulmonary phthisis of the second and third degree. In each of 

 these cases a few particles of the sputa sufficed to give at least one 

 preparation in which the characteristic bacilli were found. 



The first series of preparations were made according to Koch's 

 method. The bacteria were few and difficult to find. They were 

 feebly coloured (a pale blue), and were very small. To show them 

 clearly a very bright light, obtained by means of an immersion con- 

 denser, and the use of a good immersion objective were necessary 

 (1080 diameters). 



The second series were partly made by Ehrlich's process. The 

 bacteria were coloured a bright red by fuchsine, the rest of the pre- 

 paration being completely colourless. In one of the preparations the 

 typical bacteria were very numerous, in groups numbering from four 

 to eight within large cells, or disseminated in pairs here and there, 

 and it was not difficult to recognize the spores : often also they were 

 placed end to end in pairs. The organisms corresponded well with 

 the description given by Koch, and were perfectly recognizable 

 without a condenser and without a high power (750 to 800 diameters.) 



A few good preparations were also shown in which the ground 

 had been coloured blue. The bacteria were more easily found than 

 in the others, and stood out clearly by their fine red colour from the 

 rest of the preparation (450 diameters). 



Specimens of these bacteria prepared by Koch (on his old method) 

 were exhibited by Mr. Watson Cheyne and Mr. E. M. Nelson at the 

 two soirees of the Eoyal Society on the 10th May and 21st June, 

 and also at that of the College of Physicians, and attracted consider- 

 able attention, not only from the interest which attached to Koch's 

 discovery, but also for the excellent way in which they were shown. 



Preserving Infusoria and Amoebae.* — E. Korschelt refers to the 

 method described by M. Certes for colouring and preserving Infu- 

 soria,! in regard to which O. Biitschli in his abstract of the paper 

 expressed a hope that it would be possible to find a more suitable pre- 

 serving method as he could not place reliance on preservation in 

 glycerine. The author considers that the following method (which 

 he devised without knowing that of M. Certes) will enable prepara- 

 tions to be made which leave nothing to be desired in regard to 

 durability. 



The water in which the Infusoria are placed upon the slide must 



* Zool. Anzeig., v. (1882) pp. 217-9. 

 t See this Journal, ii. (1879) p. 331. 



