110 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



and if necessary clarified by the addition of a few drops of nitric acid. 

 To every 10 ccm. gelatin G-8 drops of formalin are added. The objects, 

 previously hardened in alcohol, are washed in water and then placed in 

 glass vessels containing formalin-gelatin cooled down to about 60°. 

 When the gelatin has set the jars are hermetically closed. 



Another similar method consists in making a 5 p.c. gelatin solution, 

 and then treating it with i-1 p.c. formalin. The objects are for this 

 method previously fixed with formalin. 



Demonstration of Cholera Vibrios.* — Prof. L. Heim states that the 

 presence of blood in the medium much facilitates the demonstration of 

 cholera vibrios in suspected fluids. A decoction of blood is prepared 

 by boiling clot and then filtering the solution. To 200 ccm. of water 

 containing cholera vibrios 4 grm. of pepton and 2 grm. of common 

 salt are added. When these ingredients have become perfectly dis- 

 solved the fluid is distributed into two glass vessels. To one is added 

 50 ccm., or more, of the blood decoction, and both are incubated for 

 24 hours. The growth in the sample containing blood is more copious, 

 the indol reaction more marked, and the motility of the vibrios greater, 

 than in the pepton-salt medium. On plates containing blood .the 

 colonies are more luxuriant than on ordinary gelatin plates, the dif- 

 ference becoming still more striking in a few. days. 



(3) Cutting-, including' Imbedding and Microtomes. 



New Ether Freezing Apparatus for the Microtome.f — Dr. A. Noll 

 has devised a freezing apparatus, by which the necessary coldness is 



r 



w 



\mS 



Fig. 31. 



obtained by the evaporation of ether in a vacuum. It consists (fig. 31) of 

 a metal chamber K with two side pipes a and b, and a bar c for fixing 



* Centralbl. Bakt., 1" Abt., xxx. (1901) pp. 570 r 3 (l,pl.). 

 t Zeitscbr. f. wiss. Mikr., xviii. (1901) pp. 141-4 (2 figs.). 



