ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



Ii09 



or better, for a quarter in an autoclave at 110°, the gelatin mixture is 

 filtered, and distributed in the usual way. 



Simple Method of Cultivating Anaerobic Bacteria.* — Dr. J. H. 

 Wright describes the following method for cultivating anaerobic bacteria. 

 After the culture medium in the test-tube has been inoculated, the cotton 

 stopper is p ished in so far that its upper end is about 1 cm. from the 

 mouth of the tube. Then a small quantity of an aqueous solution of 

 pyrogallic acid and of sodium hydrate is run in. 



The tube is at once closed air-tight by a rubber stopper. The pyro- 

 gdllic acid and water are mixed in equal bulks, and one part of sodium 

 hydrate with two of water. For test-tubes 6 in. by % in., ^ ccm. of 

 the pyrogallic acid solution and 1 ccm. of the sodium solution are about 

 sufficient. This simple method has given satisfactory results with 

 tetanus and other essential anaerobic bacteria. 



The author notes that the following points are highly important for 

 anaerobic cultivations :— 



(1) The medium should contain 1 p.c. of glucose, and should be 

 boiled, and cooled immediately before inoculation. 



'2) The medium and reagents should be freshly prepared. 

 3) The reaction should not be more acid to phenolphthaiein than 

 + 1*5 of the scale of the Bacteriological Committee of the American 

 Public Health Association. 



(2) Preparing- Objects. 



Dialyser for Histological Purposes.f — Dr. E. Kolster has devised a 

 dialyser for the purpose of dehydrating preparations at a regular and 

 uniform rate from first to last. The apparatus is composed of the follow- 

 ing parts (figs. 30, 31): — C and B are glass tubes, the outer one being 



Fig. 30. 



but a little longer than the inner one. To each are fixed twisted wire 

 supports, F l5 F 2 , F 3 , arranged in the manner indicated in the illustrations. 

 The projecting arms rest on cork blocks A A. The tubes C and B are 

 closed by membranes made of very thin paper and stuck on with albumen. 

 Into the tube C the specimen to be dehydrated, along with distilled water, 

 is placed. The outer tube B is filled with 25 p.c. alcohol. The whole 

 apparatus is placed on a large glass dish, half filled with 50 p.c. alcohol. 



* Joum. Boston Soc. Med. Sci.. v. (1900) pp. 114-5 (1 fig.). 

 t Zeitschr. wiss. Mikr., xvii. (1900) pp. 294-8 (2 figs.). 



April 17th, 1901 i 



